Ok, I'm going to get some flack for this, but I think the FE7 lord trio would actually be a really neat thing in Smash 4. D: I'm not entirely sure how you'd explain them being part of a single character, but.. It'd be neat.
You get Lyn's nimble/katana playstyle.. You can be a total BAMF as Hector.. And yeah, even though a lot of people dislike Eliwood (he's still one of my favorite lords..), you could make him a pretty dang unique character.. And here's how you do it.
You put him on his horse. No, seriously. You put him on a horse, and give him either the Durandel or a spear(kinda like the idea of spear better, since then they'd have the weapon triangle sword-spear-axe, but Durandel is more signature for Eliwood probably). He'd be unique in that he'd be unable to grab the ledge. In return though, he'd be fairly heavy, have a high midair jump, and his Up B makes his horse leap far into the air (and not put you into freefall). He could also have Side B be a horizontal recovery-esque move that could act as a charageable dashing move kinda like the Paladin crit in FE6/7/8:
Then their Final Smash could be a triangle attack type thing.. I dunno. I think a Eliwood/Hector/Lyn trio would be an awesome thing in Smash.