Everyone knows how GG's been made now. This is blue hair, it's really not the same amount of work as another character. It's more work than a regular costume in a different game and it's not like we're expecting a costume for every character but this really shouldn't take up another slot to colour some hair blue. These guys don't use different moves in the show in SSB and what does change can be incorporated as different attack cutscenes. You know, never mind. I love the idea of Kid Goku, SSJ Goku, and SSB Goku all being on the same team like a bad MUGEN game.
You realize what you're basically saying right? They take up more work than usual but not as much as other fighting games. But this still saves them time and pads out the roster a bit. This isn't taking anyone's fucking slot lmao. They could also change the mechanics of them a bit too. They are also wearing different costumes so it still takes up much more effort than just coloring some hair. At that point they might as well give them different moveset even if it's not widely different (but see other fighting game clones where tweaking a few things can drastically change the playstyle for a character)