I think the biggest issue is that you have a bunch of SIM recruits who are not athletic nor are the strong defenders. Simply put, the team you inherited is not very good.
As an aside - why did you only recruit juniors and seniors this season instead of freshman? You did a good job recruiting strong players at Cal Tech the season before (I know this because you got Fischer away from my DIII team (my alias account)), so I know you now how to recruit good freshman.
The lineup you used last game is actually one of your strongest. I'd probably run the following and hope for the best:
PG: Tilley, Stringfield, Ball, Marshall
SG: Stringfield, Roy, Ball, Marshall
SF: Ball, Roy, Cottingham
PF: Widner, Wells, Rosson
C: Brown, Rosson, Widner/Wells
I wouldn't play Barton or Hobson at all. They aren't going to help you much.
I'm guessing you probably want to get to DI quickly since you jumped to DII after one season. Staying at DIII for 3 or 4 seasons isn't a bad idea before jumping to DII, though. You learn a lot about the game and your good recruits at California Tech would have helped a lot. Best of luck!