On Lucas: he, Ninten, and Ness are just PK users which makes them difficult to be different. Hell, even Kumatora would be a bit difficult since the difference with her besides being a girl is that she fights with her fists in Mother 3 while Lucas, Ninten, and Ness all use sticks, bats, yo-yos, and other stuff kids can buy or find around town. She'd basically be Wolf in that her normals and smashes are different while her specials are just variants of Ness and Lucas. Claus would work since he uses a sword, but he's basically a walking spoiler for the many unaware of the Mother/EarthBound series. The other party members could work, but they're not that well-known even compared to the obscure protagonists of Mother/EarthBound.
Mother/EarthBound is a great series, but one where its characters, well, main characters, are just way too similar.
On Wolf, Falco, and some other Star Fox character like Krystal, Leon, Peppy, Panther, and dare I say it, Slippy: Krystal is many people's choice for a Star Fox character who cannot or shouldn't have a cloned move set. Why? Star Fox: Adventures despite the fact her staff never shows up in later games. The staff alone sets Krystal apart from everyone else and hell, it'd be easy to reference Adventures and take all the abilites and moves to make Krystal. The issue is making her which means time and money.
Wolf is more like Ike is to Marth than Roy is to Marth. Wolf's and Ike's Specials resembles Fox's and Marth's respectively, but function differently. Wolf's and Ike's normals and smashes, however, are different from Fox's and Marth's. So, I never really understood why people say Wolf's a clone of Fox (and Falco), but few say the same about Ike. That said, with Wolf's background and "aura", his Specials should have been more dirty compared to Fox and Falco. He's the anti-hero, the rival, and sometimes the villain. I feel that Wolf's Specials should have involved stuff like grenades, caltrops, a shotgun instead of a blaster - as kid-friendly as a shotgun can be -, a pounce-takedown instead of an illusion - or an illusion-assisted pounce -, and other feral, deceptive, and underhanded tactics. As for a Final Smash, couldn't he just snap his fingers, laugh, and have his Star Wolf team carpet bomb everyone? Come on, it'd tie in with his dastardliness.
Falco, on the other hand, makes sense with having the same gear as Fox, but Falcon's own flair is what makes him unique. Still, I wished that his Final Smash involved an Arwing since he's the ace pilot of Star Fox. Also, I think Falco should trade his Fire Bird with Wolf's Fire Wolf. Why? He's a bird and Wolf's Fire Wolf looks more air based than fire - I think the Japanese name, translated as "Wolf Shoot" makes more sense. It could be called Air Bird or something. Basically, a faster, more vertical lift compared to Fox's Fire Fox. Hell, change Falco Phantasm's animation so it looks like he's diving like a Peregrine falcon and call it "Falco Dive" and allow Falco to angle it down (or up) when in the air. I bet Captain Falcon would totally approve.
Now that I think of it, did Falco take Wolf's move set in Melee since Wolf was originally planned for Melee? Y'know, Wolf's Specials make more sense for Falco. Hmm...
TL;DR: Ideas and thoughts on Lucas and Star Fox characters.