How about removing the 3-2 zone?
I'd also suggest removing the basket from basketball and just have guys run around with a ball.
All jokes aside, I'd prefer the idea of having even more defensive options like in the real game (Triangle-and-2, Square or Diamond variants of Box-and-1, half court pressing or flashing etc). Nonetheless, with each tactic having glaring weaknesses (GL using Triangle and 2 vs a good outside scoring team, and baseline cuts and drives vs a 3-2, low post to high post cuts and wing/corner 3's threat vs a 2-3 zone...).
Like how in offense, Passing becomes an even more important skill for tactics like Princeton, the game engine needs some potential revamping concerning how defensive values or defensive tactics deal with Driving, Shooting, Passing (Positioning perhaps as well). Which would give an greater incentive to scout the performances of other peoples games. Should I use an appropriate defense vs a team that seems to drive well to the basket, but shoot poor wide-open outside shots? Should I abstain from going a 2-3 zone because their PF seems to be chucking 3's non stop?)
Obviously, difficult to implement a rather intuitive game through mathematical equations.