Well, realism would be paradoxical in this case. In a real scenario, I would be able to control the amount of minutes my players play in the scrimmages more efficiently and effectively. Hell, its a scrimmage. Nobody would give a crap if I put some random D-leaguer in. But in BB, if I want to do that, I need scrubs to fill in, otherwise, the "coach" will keep making my players play, even if i set them to only backup.
So, while its realistic, its not realistic - because acquiring and getting rid of scrubs each week is not realistic. But it's the closest BB allows you to do to using D-leaguers. And it makes scrimmage training minutes more realistic.
Anyways... great week for two of my best players to get injured. Playing the #2, #1, #2, and #3 teams in their respective conferences. And my game against you is televised. And you're my rival. Since my merchandise is already suffering (How can I be undefeated, last 5 weeks in the cup, make it to the finals last season, own 7 out of the conference's 10 all stars, not have sold a star player this season, and still not have good merchandise?!? ...I know its not affected by all stars, but it should), I can't afford to lose that game :P