In general, I'd stay with Baker, his advantages in SDP and DE make him a better defender at guard, and the two players are very even offensively. They are so close, though, that I don't think the choice will make or break you.
However, if I was facing a press I would probably start Howell, hoping his superior IQ and BH would slightly lower the turnover rate. (I juggle my lineups a lot based on this kind of thing.)
As for the STA concern, it shouldn't matter a ton if you are subbing based on fatigue instead of target minutes.