Uh oh, my field, I was a pianist for 5 years, I still play regularly, Tocato & Fugue*however you spell it, too lazy to check* in D minor, yes.... you'll understand when you hear it. Anyways, tucking your thumb under your first- through - ring finger's a bad idea, any pianist knows that you never cross fingers, and that you use all of the fingers you can, because you'll get the most reach *aka, don't skip out on that ring finger, I know I do it a lot, and it kills me sometimes*
BUT: anyways, my point is, with the neo geo layout, if you do it like a REAL neo geo layout, you actually rest your thumb on the bottom left button. You never use your pinky, because your index through ring finger control the 2-4 buttons. It's much harder to see how this works on a Neo Geo arcade as it is to see on a Neo Geo arcade stick *for the console version* That's how I have my layout setup for on my cabinet, and it works beautifully even with the extra 3 buttons, since they're actually resting under your hand.