I think it is that the players have pretty good stamina. When I first started, and had lackluster stamina, I think I had better rotation - but that just mean my starter was getting gassed.
At several of my positions, my top two players are pretty close to each other in ability. I can reverse the two and it doesn't end up that much different.
My starting PF will play about the same amount of minutes, even if I reverse the two.
My SG I can do it one way, and the starter will dominate (45-3). But I can reverse the two and it might end up 33-15. In this case, the one SG has slightly better outside skills, but not by much.
Game shape appears to also have a big effect. I've managed to get 10 players for strong/prominent, but I'm having trouble getting minutes for the others. Because of their GS, they don't like to come into the game so I can't build up their GS.
Maybe BB will need to make players tire faster, so that their performance will decline enough that a fresher player will outperform them.