Thanks Scherf! So it's pretty clear that the inner tanks are the best for agility. It's less clear whether the auxiliary or outer tanks are the worse ones to have for maximum agility. I would say it's probably better to have the extra pitch stability, than the extra roll rate.
As far as the fuel tank sizes go, there's an inconsistency between those in the literature and in AH: The Mossie in the game has 170 gal. inner tanks, 70 gal. outer tanks, and 60 gal. of AUX fuel.