Boy oh boy, and I wanted to get some sleep.
Let me also start the conversation of wasted character slots, such as Dr.Mario, Dark Pit, and Lucina. Those characters are wastes of character slots, and could have easily been simple outfit changes. You know, like they did with bowser jr, or olimar, or Robin, or wii fit trainer? They could have added actual characters with great potential, rather than these clones. I for one would have loved the return of Squirtle, or the re addition of Mewtwo, or Roy? But instead they got wasted on clones.
Okay, let's start off firstly by saying you completely contradict yourself. "Lucina is a waste, why didn't they forget about her and add back Roy?" Do you even know that Roy was literally Melee's Lucina? Hell, Roy was MORE of a clone; the only big difference was that his sword's sweetspot was the hilt, and not the tip, whereas Lucina actually has functionally different attacks as well as a different sweet spot and range. Also, Mewtwo was literally one of the worst and most broken (technical-wise) characters in Melee, bar Pichu, and everybody complains about him not being in the games for one of four reasons:
1. They're being ironic and doing it for kicks
2. They think that Lucario replaced him (he didn't? Lucario plays much better and is much more interesting than Mewtwo anyways)
3. They want to nitpick because Sakurai has to make sure EVERY CHARACTER EVER PLUS THEIR GRANDMAS APPEAR IN EVERY GAME
4. They're doing it because everybody else is and want to fit in
All of which are stupid. Don't do that.
Now onto the topic of the clones and them being "a waste". Simply put, you're wrong in every possible way. Sakurai himself admitted that he added the three "clones" in because they took less production time then one full-fledged original moveset character, and guess what? They literally all play different to their "original" characters; Dr. Mario is Melee Mario, weighing much more and dealing much more damage with his moves, along with a different DownB, and a different functionality-wise UpB. Lucina is functionally individual and calling her a clone is like calling Falco or Toon Link a clone at this point (just because movesets are similar doesn't mean they're exactly the same character), and Dark Pit even plays different compared to regular Pit, thanks to his custom sidespecial, more damaging but slower and harder to turn bow, and lack of an infinite.
And what's up with Gannon? Why is he exactly the same as he was in brawl? You know, the worst character on the roster due to his dumbed down moveset that mimics captain falcon's, except much slower? Gannon has so much potential, but they treated him like an old potato, and simply left out his glory. I mean, he could have used magic, or his swords, or anything other then a falcon punch/kick, which is weaker then the actual falcon punch and the Mii brawler variation of the falcon punch.
You realize that Ganon is considered one of the best characters in the game currently, right? Maybe you just don't know how to use him? Or maybe you're just upset because "boohoo his moves have similar functions to Falcon's". Get over it, honestly. The only clone complaining that isn't "whining for the sake of whining" or "whining without understanding completely what one is whining about" is Pichu being a shitty clone of Pikachu.
Sm4sh has 15 completely original new characters (counting all three types of Mii Fighters), even more if you count re-designs like Pit and Charizard as "new". Don't whine about how three characters have similar movesets to other characters when A. they are completely different in functionality, B. It was either them or none at all, and C. There are 15 new god damn characters.