Alright, so I need to get the Oendan trophy/stickers/EBA stuff.
With those three non-SSE characters, you walk into a door, it goes to a quick cut-scene of that character on his/her stage, and then you fight and unlock said character. They have no impact on the story, and you have to have beaten the game to make their doors show up.
I'll nab pictures of all the hidden stages that I remember are hidden and aren't on the Dojo yet. I don't have the patience to deal with videos, though. None of the clones are as close as the melee clones, though. The closest would be Toon Link, Ganondorf, and Falco. Toon Link is actually more different from Link because Link changed a lot, but he's very similar to Young Link. His Bow is better, but his boomerang isn't as good. Ganondorf's a moves look more Ganondorf-y, but they haven't changed so much. His forward B now grabs, rather than uppercuting or hitting down, and his Up+B still grabs, but has a hit at the end of that. Other than that, he's about unchanged. Falco's down+b, as you likely know, has changed.
Like I said, I'll take pictures of the stages, I know I've unlocked them all, you get a message. I've also unlocked all the AT's, so there's no question about that. The last trophy I unlocked is from Band Brothers.