It's still nowhere near the lines of Mario, LoZ, or Pokemon, in fact the series has sold less than Mario, Pokemon, TLoZ, Sonic, Wii, Wii Fit, Metal Gear, Pac-Man, Donkey Kong, Final Fantasy, and even Smash Bros. itself. Imo it shouldn't share a fighter count with Mario, Zelda, or Pokemon. And almost all Kirby characters not in Smash only have one major appearance, (Adeline, Marx, Magolor, etc.) We shouldn't get more than one one-time Kirby characters.
Edit: The only area where the franchise is popular is in Japan, and there it's not really his games that are popular, pretty much just his character.
I had more fighters for Mario and Zelda but I wasn't sure how they'd be received (they're kind of personal picks)
Wii games are represented with the Miis
Wii Fit has no eligible fighters other than WFT
DK has sold great but clearly Nintendo isn't pushing it as much anymore, and there aren't many characters to choose from outside of the ones listed.
Smash Bros itself? What, is Galeem a fighter (that.....that would be cool actually)?
Third parties shouldn't even be in Smash IMO. Neither should retro series.
The point I'm trying to make is yes it's popular in both the west and japan, look at the ballot results. It has sold roughly 40 million copies, which is a lot. Unlike other series, there's very little redundancy in the design and moveset potential of it's characters.
- The series sells well
- It's very popular
- The characters would all bring something new to Smash
- The characters are all designed in their own unique way
And no, the characters you listed don't have one major appearance. In fact, all of the characters you listed have appeared several times
Adeline: Boss in DL3 and 64, playable character in Star Allies, various cameos otherwise
Marx: Boss in SS, SSU, Mass Attack, playable character in Star Allies, various cameos otherwise
Magolor: Boss in RtDL, helps Kirby in KCD, playable character in Star Allies, various cameos otherwise
Besides there are plenty of characters on my list who made smaller appearances or are truly one offs. Rex and Pyra, Skull Kid, whoever the rotating fighters are for Pokemon and FE, etc. all have small appearances.
If you don't like how I organized it great. Go make your own roster with less if you want to. I've explained my reasoning here.