I looked at the box scores of the games from the FIBA website. Then I added 4-6 minutes to each player because 2K is on a 48 minute scale rather than 40 (240 total mins vs 200).
The next step was over-exaggerating the minutes of some of the bench players and under-exaggerating the starters to make sure the guys off the bench were playing enough during gameplay. In simulation the numbers always looked good, but in game it was a different story with the bench not playing enough.
There was also a thread a while back somewhere here on OS that talked about staggering the minutes of starters by increments of 5 to avoid the line change subs that we see so often. I wanted line change subs for USA initially so I intentionally bunched up the minutes of the starters.
I don't think I ever completely figured it out, but to answer the question that is how I did it.