If you look at SIM teams, almost all the players are in the low 2's for GPA (2.0, 2.1, 2,2, 2.3, etc)
I am pretty sure that SIMs use 5 minutes in Study Hall for freshmen and only use minutes for players who go below 2.0 for So, Jr, and Sr players.
When I have taken over SIM teams at the end of the season before rollover, I think that is what I saw.