I agree with TP here. The answer is in the number of players in your rotation. Mess around with 8 and 9 man rotations and set your bench players to dual positions in their backup. I try to set an 8 or 9 man rotation. I have 12 players on my roster and I basically omit 3 players per game. I view my lineups as an "A" lineup a "B" lineup and a scrimmage lineup. My core training players get 60 minutes per week in an attempt to target the gs to proficient.
the tough balance is playing the #1 team and #2 team in the same week. Or when you have two road games, because it seems like starters get more minutes on the road.
Good luck.