Sorry, I'm confused a bit by what you mean when you say three out of nine.
If you mean Dark Seamus, K Rool, and Ridley I was referring to whent in previous games we've only got up to two or one villain being introduced as a playable character(s), (I don't count Wario, Dedede and Meta Knight in Brawl, they're all at most an anti-hero these days despite what the K Rool trailer says about Meta Knight, similar reasoning goes for Dark Pit. Nor do I count Mewtwo since outside of the anime, like most of the Pokémon he's neutral, only reason he fights back when someone's trying to capture him is out of self-preservation since I'm quite sure if anyone was an animal that's not usually kept as a domestic pet you wouldn't want to be captured. I would've clumped Wolf in here too if it wasn't for the fact recently he's being portrayed in his villainous roles of old again since post assault he's been more of an anti-hero until that Star Fox 64 remake, Zero, and now Starlink released.) So in all we only had
Melee: 2 (Bowser, Ganondorf)
Brawl: 1 (Wolf)
Smash 4: 1 (Bowser Jr.)
Then in Ultimate so far we have 3, K Rool, Ridley, and Dark Samus.
So when it comes to smash games (more so modern ones) three villains certainly is a lot, but as my post says Cranky is infact a redeemed villain, a hero nowadays. I just listed his past as one reason I'd like to see him get in smash one day so the OG Nintendo villain got the love and respect he deserves, since without him we wouldn't even have the villains we know and love that are currently in Smash bros, heck that could go for most of the characters in Smash actually.
But if I'm wrong on my assumption... could you please elaborate?