I dont see why not....If what your aiming for is simply changing Zelda's Transform into Super Sonic with his attack abilities, then u would indeed need to replace Sheiks Model with Super Sonics Model, then, replace Sheiks Attacks and motion with Super Sonics
I do however, have a problem with what your proposing, By Replacing Zelda's FS with Sonics, it may glitch and stick u. I haven't tried something like this, so I can't say for sure what will happen. Just try it and play around with it.
Sorry for the delayed responses been busy revamping dark sonic. (which is going well btw, still need a few animations and attacks and he'll be ready for a beta release) but I'm afraid there's a bit of a misunderstanding here.
I want to replace Zelda's final smash with an edited sheik model, and transform her "light arrow" into a transforming final smash. Then give it a moveset and such like Super sonic does.
I want to do this for Dark Sonic's final smash, but I need to make some animations for it >_>
Would any of you be willing to make some animations for me for sonic? Note I mean from scratch(so no worries about the tedious shoulder rotation issue) and they're pretty simple.