Players have to PAY a decent amount so they don't overuse it (then again someone will debate saying then only rich people benefits, well maybe can try find solution to that)
That's exactly what I was going to debate and I personally don't see any solution.
I would say having one guy lacking in a skill that the team overall has enough of is not as big of a problem as you think.
If your C has atrocious passing and your PG's have strong passing, train them together or train two other players who could use some passing instead of your PG's (do it when you play weak opponents so you don't lose because of a scrub playing PG)
And remember, there is a lot more difference between atrocious(1) and pitiful(2) than between strong(8) and proficient(9), so your C will train "faster" than your PG's in terms of on-the-court play (as opposed to skill levels). Of course if he's taller or older that will be negated by the training being slower to begin with, and while jumping from 1 to 2 is more impactful on performance than a jump from 8 to 9, we cannot say the same of salary, so that might also be a problem.
Everybody faces the same dilemmas. It forces people to make decisions they don't necessarily want to make, which is a big part of what makes your opponent unpredictable and fun to play against.
"Air is beautiful, yet you cannot see it. It's soft, yet you cannot touch it. Air is a little like my brain." - Jean-Claude Van Damme