It does matter quite a bit. We already know there are obviously commands that use multiple buttons. There needs to be a standard layout so all multiple button commands make sense are are readily available.
It’s like in SF4, you wouldn’t make a FA be performed by pressing 2 buttons, one where jab is traditionally placed and the other where roundhouse is traditionally placed.
You’re not going to play with your buttons randomly assigned anywhere. You must be a pad player to not understand the significance. Use your head sometime.