Diddy's, Pikachu's, and Sonic's are all VERY DIFFERENT. Diddy flys around shooting peanuts, Pikachu is a hard-to-control ball that can go through obstacles, and Sonic is somewhat similar but he can't go through stages and the like. They're really not essentially the same at all.
Also, Eric, Wolf is not a clone at all pretty much. Him, Fox, and Falco are all pretty different. He isn't as fast, and all his A's and B's are different pretty much. They're Luigi(s) to Mario. They've been altered a good amount. It's not like Melee, where they gave Fox a new look and tweaked a stat or two and called it Falco.
Also Carius, I agree. I think it's cool how they're emphasizing that.