7 pilots per airframe is completely unrealistic. In most bases each airframe does 2-3 turns per day, which requires four pilots. You also need two pilots to cover AM/PM resv. You're already at 6 pilots right there, and then you need to give pilots at least 11 days off, so now you're looking at 9-12pilots per frame, depending on how the utilization goes on a daily basis. Adding additional frames to a base might lower the pilot per/frame due to fewer reserves needed, however it seems like a 1:3 ratio of reserve line/flying line is the max you can go. That said, going to more and more small bases only decreases efficiency.