One of the best fighting games ever, but actually unplayable without adjust keys. Jump button should placed on top (Y gamepad button). I Know your criteria is adopted for many games, but is simply wrong and unnatural. In facts, lower button can be used for duck, slide, pick up or elseware in some games.
All my games are edited with Jump on top, sometimes I use Xpadder, other times XInput Plus (sites.google.com/site/0dd14lab/), but in that case the modified dll does't work in unity games directories. :\
The perfect config is to put kick on the right (B) becouse, imagining the player usually facing to the right, are longer than punches (X) and can be confortably pressed with kick (also together in some games) for flying kicks.