The ultimate challenge of building an offense at the college level is that you are working with college students. It's not high school ball where the parents are looking over their kids' shoulders to make sure they are giving it their all, it's not pro ball where the financial need to make as much money as possible in a short window of time is a constant motivator for adult players.
It's college, where many of the kids are looking to explore and have fun. What's more, you get them for three-six years only and you can't be sure when they arrive on campus which of those extremes might be possible. Their previous level of competition has not prepared them so you can usually count on their first one to three seasons being development years before you harvest the results for one or two seasons.
That calculus makes the art of developing an offense a real challenge, since good offenses operate primarily through developed skill rather than sheer athletic talent.
Developing timing between QBs and receivers to nail down timing routes, chemistry between OL to execute double teams and blocking schemes, and experience from backs in knowing how to manipulate defenders and find the holes, these things take time.
So the simplest strategy for having a productive offense is to have a quarterback who can use his legs to scramble and pick up yards, buy time to hit receivers, or to open the world of arithmetic-simplifying QB running schemes.
But not everyone has those guys, and the NFL isn't even particularly looking for such players, instead preferring guys who can make complicated reads, difficult throws, and stay healthy. Some major college teams than often spend time searching out and developing statuesque QBs with pro futures, others can't win those recruits but also can't count on having a dual-threat to make their system work.
Going the route of choosing pro-style passers can have the negative result of having a run game that suffers because either the QB can't run the option or featuring his talent with a developed passing attack requires so much practice time that the run blocking is neglected. Or perhaps the team simply can't time the years when their fantastic but immobile QB is healthy and developed with the rest of the team being up to snuff.
Faced with similar challenges, high school teams often just stick the best athlete at QB so he always has the ball in his hands and then run whatever offensive sets allow him to run amok.
How do colleges who don't have the cheat code of a dual threat QB handle these challenges? The key is being able to check off core competencies for a successful offense in general.
Those can be seen in Bill Connelly's "five factors" that determine who wins the football game. From those factors we can deduce that a team's strategy with their QB needs to be efficient in terms of picking up first downs, explosive, effective in the red zone, and not turnover-prone.
If there's one place where the dual-threat QB can struggle it's in the turnover department where fumbled options, bad ball protection on scrambles, or ill-advised throws on the run can lead to ruin.
So what are the main strategies for building an offense with an immobile QB that check off those key competencies?
1. Run the ball, throw off play-action
If you don't build around the QB position you won't be ruined if he's not great. If your passing game is simpler in nature, you won't be at the mercy of having a redshirt senior QB in order to win football games.
With a ground and pound attack that relies on the OL and RBs most snaps and creates the opportunities in the passing game off that action, teams can build a system in which the QB is more of a cog than an engine to success.
Arkansas is currently ranked 20th in offensive S&P despite having a statuesque junior QB that no NFL teams will be calling up. They are efficient on offense by having a strong running game that makes their passing game simple. When they do throw the ball, it's usually out of bunch sets that make defensive coverages simpler and often get WRs a free release, or off play-action.
From the same set they could run one of their lead schemes like a wham zone run. The H-back and Y are tight ends who can block or run routes with some degree of proficiency:
From the same set, the Hogs or a similarly designed team can run a route combination from that bunch set that makes it hard to jam receivers and stop them from getting a clean release. In this instance, the only receiver you can jam is the Y and that's a big, powerful TE who a DB or LB isn't going to be able to jam super effectively:
Running play-action from these types of offenses still favors a QB with enough mobility to run waggle or bootleg plays but that is a lesser range of mobility than is needed to scramble or run the option. These types of plays are excellent for converting shorter-yardage situations since they put linebackers in run/pass conflict and allow separation for receivers that makes conversion of a short passing game very efficient.
Ultimately, the simpler your passing game the more complicated your run game can be. If you can consistently develop good OL to execute a variety of run schemes that will provide an efficient attack and leaves a smaller role for your unathletic QB to fill.
This also helps the offense avoid being turnover prone, since easy read passes and runs don't risk many interceptions, and power running games usually thrive in the red zone. In fact, spread teams often get into big power sets once they approach the goal line.
The challenge is in creating explosive plays, these need to either come from the RB, or more likely, from deep play-action passes. This is where things get tricky, as completing deep play-action passes usually requires some arm strength from the QB as well as some weapons at receiver that can win one-on-one match-ups. The better the running game, the easier it will be for receivers to find open spaces regardless of their talent level and the easier for the to find and hit them.
2. The spread passing game
Building a running program that can consistently up bruise opponents in the trenches and beat them with mis-matches on the outside is a difficult approach that many programs have understandably eschewed.
What if you can't field enough good OL to count on beating teams in the trenches? What if the tall, strong-armed QBs aren't interested in your program and the tall, fast receivers are following them to other destinations? What if you don't have consistent access to the freak I-back who can carry the ball 20-30 times and dominate a game?
Hopefully in this instance you can recruit a dual-threat QB...or you can pick an immobile guy without NFL skill and focus on the spread passing game. Some teams will focus their efforts on a ball-control passing game from pro-sets but this requires having studs at TE who can run routes. It's much easier to run the West Coast style passing concepts as the main feature of your offense if you spread the field with athletes. The receivers have an easier time getting open, you can use different types of players at WR, and the QB has a cleaner picture to read and is thus less likely to throw interceptions.
For years at Texas Tech, Mike Leach didn't even recruit to the level that was possible for the university because he knew the types of player he needed to make his system work and focused on snatching them up without concern for whether he was getting the biggest, fastest players available. It made it hard for his coaches to field good defenses, but the Red Raiders didn't struggle to put up points on offense.
His solution, and the spread passing game solution overall, is about using carefully honed skill to execute a passing game that can provide efficient play, has answers in the red zone, generates explosives plays, and is good at avoiding turnovers.
Now, some spread teams have evolved to use "Spread-I" tactics to get the benefits of a power run/play-action system of offense, which is simply the easiest method for controlling and winning football games. These are becoming the superior tactics, however there are still other methods to win without mobile QBs.
Controlling the ball and moving it down the field efficiently requires a passing game that has answers for how to attack the whole field and stress the defense, how to answer the blitz, and how to create explosive plays. Doing this often means that the run game is more neglected with personnel choices (emphasizing pass protection from OL prospects) or practice time (nailing down timing and chemistry in the passing game over chemistry on zone blocking).
However, the rise of route adjustments at the college level combined with up-tempo practice habits are allowing teams to more quickly develop QBs and WRs who are proficient at a passing game that can check off all the boxes. This greatly reduces the stress of having a senior QB, top WRs, and a veteran on the team all at the same time while also having a defense strong enough to support the offense in a quest for a title.
The best spread passing concepts today for checking off all the boxes are basically endless variations of the "four verticals" passing play that really took off at Houston where Leach-tree coaches like Art Briles, Dana Holgorsen, Kevin Sumlin, Kliff Kingsbury, and Doug Meacham all spent time.
Essentially, the play has evolved towards playground football where the receivers all start with vertical stems and then break off their routes based on the defensive coverage. It's then incumbent on the QB to read the coverage and know where his match-up wins are and where his receivers have leverage. Here's an example of how the routes might adjust against a 2-read coverage by the defense:
The "X" receiver sees the CB stay underneath him so he continues upfield to threaten the safety. "H" is facing inside-out leverage from the linebacker so he breaks to the sideline on an out route. "Y" sees the middle of the field is open and attacks the space between the hash marks while "Z" find himself facing soft coverage from the corner and turns to find the ball on a curl route.
Those "Y" and "H" receivers could be big, receiving tight ends but they could just as easily be little water bug receivers like Texas Tech's 5'6", 169 pound Jakeem Grant. Some teams prefer the latter in homage to Mike Leach's old adage "throw it short to people who can score." One easy way to generate explosive plays is to consistently put the ball in the hands of explosive players.
In an offense like this, having a cerebral QB who's simply accurate, capable of quickly making decisions, and has enough of an arm to throw the different routes is all that matters. If he has a great arm? Alls the better, but it's not essential. Is he mobile? It doesn't hurt if he is but it's not essential to make the scheme work.
That said, the receivers better include some playmakers because even a highly proficient passing game will still struggle to get down the field without big passing plays and those come most easily in this system either from WRs who can win deep throws or who can tear up a defense after the catch.
Summary: You gotta have playmakers somewhere
No system is immune from the need to have great players who can do something with the ball when they find it in their hands. If that player who can make something happen through sheer athleticism has enough skills as a passer to put him at QB and have him touch the ball every play? Well that's sure helpful.
If not, and a team has an immobile guy playing QB then he either needs to be able to fling the ball downfield to maximize opportunities from teams focusing on stopping a stud athlete playing RB or he needs to be a savvy practitioner of the passing game who knows when and how to get the ball into the hands of a playmaker running in space downfield.