You need more power?! You already have power!
But I'm not a Super Mod like IsmaR.
Ryu in SSB wouldn't be that crazy. Hell, technically, Mario, Luigi, and Dr. Mario are somewhat similar to him. I wouldn't be surprised if Mario, Luigi, and Dr. Mario's movesets were inspired by him. I mean, it's Street Fighter, the fighting game that along with Mortal Kombat, is known by tons of people young and old. The only difference would be translating him from Street Fighter to SSB which seeing how Mega Man, Wii Fit Trainer, and Villager were translated from vastly differently game styles, still work and work beautifully. It'd be hilarious if Ryu from Street Fighter didn't get in, but Ryu Hayabusa in his retro look and style got in instead.
If Roy returns and ends up having the same moveset from Melee, he's already a semi-clone by how his Flare Blade is animated and works along with Counter's animation. He'd be the Dr. Mario to Mario and in a way, would be the "opposite" of Dr. Mario to Mario. Marth wants to space and play it safer sort of like Dr. Mario while Mario wants to go in and tear you to shreds. Knowing Roy's centered hits mechanic, he'd be perfect for rushing in and dealing a ton of knockback and damage. Roy's name wouldn't be much of an issue even if it's reused from Roy Koopa for his character pick and victory announcements. He would get complaints of being another clone added in... Oh well.