If you've decided you have to give him a few more chances against RHP (because of his contract, preservation of team morale, loyalty, whatever...) and want to spread them out, assigning the starts based on vs. pitcher x splits is no dumber than just doing it randomly. Since Hall probably has some recollection of whether he's hit a pitcher or not, you might even be scoring some brownie points with him by "putting him in a position to succeed". I guess I agree that it doesn't matter how he does it if he is going to do it. I will say however that I would prefer Macha give Hall a chance to succeed in place of Counsell instead of Gamel. Over that I would prefer Hall never start against RHP.