Will make the game [censored], will be exploited badly.
Player x is playing badly, half way through 2nd quarter, told to fake a hammy in 5 mins time, does that, brings on sub who plays better.
leave the bench at 4 and if you lose them it's just bad luck.
If anything they should cap the rotations so it's less an advantage and prob slow the game and less hard hitting collisions throughout the 4 quarters.
20 per quarter is plenty I think.