Yeah, semi clone is probably the best term. What I mean is that Wolf and Fox were only clones in terms of their specials, and even then the similarities were mostly superficial. The same thing is going on with Ness and Lucas. They both have a PSI Magnet which absorbs energy, but Lucas's has a damaging hitbox at the end. They both have a PK Fire, which sends out a little thunderbolt and burns people, but Lucas's is more of a disrupter rather than a setup like Ness's. They both have PK Thunder, but Lucas isn't ****ed if somebody intentionally goes out and gets hit by PKT1. They both have an exploding, chargeable PK attack, but Lucas's is faster, weaker, and I mean just has a totally different hitbox.
Then we move into standard attacks, and aside from FSmash they're totally different.