If you shave two pixels off each side of the portraits, you can fit everyone in one screen on the 3DS, with room left over for two big Random buttons that I didn't feel like drawing (the one on the left would work like the Melee random where it picks one and you see who it picks, and the other one would work like the Brawl/4 button where you don't know who you're gonna get until the fight starts). Or some more characters.
(Ness and Lucas are high-fiving now; that's adorable.)
I also made this one while I was at it, and forgot to leave room for a random button. Maybe it's on the bottom screen.