It's SEGA, my man! Let's not forget the 3 button variety only had... 3 buttons.
This 6 button pad has the same amount of buttons as a PS1 controller believe it or not, it's just a different layout.
Oh, and the buttons on the bottom there aren't traditional SEGA controllers. It's a Home button, Minus (select for the games that need it) and a Screenshot button (for Switch mode, but can be reassigned in other modes.