And you have some other guy of the same caliber to start at the 2? I dunno - if your team is good enough offensively I'd be tempted to go with A against teams that didn't have a great scorer at the 1. I think his BH will limit the turnovers and help your overall offensive efficiency. It would definitely be a matchup thing, though. A against non-scoring PGs, B against better scoring PGs.
Of course, things you left out - offensive IQ and LP - are very relevant here.