If you're going to have 3 Marios, make sure they all feel unique. Doc feels different from Mario, so I approve, I doubt Paper Mario being a clone so I wouldn't mind if all 3 were playable
My opinion on the current clones:

Is the same as

Is much different than

. Especially recovery wise.

Is the same as

(Though I've heard other people argue otherwise.)

Is a lot different than

Has

moveset, does something completely different with it.

I don't even have to explain this.

Is different enough for many people to not consider him even a semi-clone

Is my main, but I cannot get the hang of

. Coincidence? I think not. The two links play much differently, so it's possible to master one, while being terrible with the other.
That's all the clones and semi-clones in ssb4. Only two of which play exactly the same as their original counterparts. As far as getting every veteran back, it would go like this:

Contrary to popular belief Wolf
not a semi-clone. Lucas is so close to not being a semi-clone, Wolf is so close to being a semi-clone. Get it? Got it? Good. So I bet you're wondering why I put him here.........I don't know myself.

Would play differently because of his gimmick.

See Pichu.

Would be the middle ground between

and

.
We are once again left with only two characters that are the same as their original counterparts.