When the majority of your passes are <10 yards, your completion percentage increases, but your odds of scoring through the air decrease because of those same limitations of being able to stretch defenses.
Stidham will solve our >10 yard pass woes and our inability to score through the air. Defenses will be forced to cover all areas of the field, which opens up running lanes, which ultimately brings that balance we've been missing and it won't be because of a magician play caller.
It's interesting Marshall had the same two offensive coaches as White, yet Marshall threw several 20-40 yard (and even 57 yard) spirals on target. Yes there were some thrown off target by Marshall. Point is he was allowed to throw far more of those than White with roughly the same run-pass ratio.
The capabilities of the QB, more often than not, dictate play calling. Another similar example is Sims/Coker vs. Hurts. Same play caller. Yet the latter QB can't throw those 20-40 yarders accurately with consistency as the two former QBs so often did, thus why Kiffin's offense was handicapped with short passes throughout last season.