The problem with these guys with real high usage, like close to 40, is what happens when he's not in the game. If you were playing the games live and making your owns substitutions maybe you could work it out, but with the sim making the subs you could end up with a 38 in the game and your team is at 110, and then a 17 replaces the 38 and you're down to 89 usage for the 5 guys in the game.
OR
The 38 is in the game with other high usage guys and you add up to like 124, which means each player is getting his possessions cut by a lot.