I dont want an analog stick though, and the joycon is too small for my hands.
If I can use some kind of an adapter to connect the Wiimote to my Switch AND it works ok then I will.
Well, sure. Not having an analog stick is objectively worse in Smash, and it is a lot worse - though in this game maybe it won't be as bad, because of how much better dashing is than walking. Do you have to double tap the D-pad do dash on the Wiimote, though? That would suck anyway.
Regardless, there won't be any kind of adapter. Nintendo has already confirmed that the supported controllers are Joy-Cons, Switch Pro and GameCube, nothing more.
Probably pro controller. It's a real shame there's no controller option with a stick layout similar to the Wii U Pro; having the Right/C Stick directly next to jump was amazing.
Well you could always customize your controls, but not having the B attacks on the B button sure would be strange. Personally, I use the shoulder buttons to jump, so I'm good either way.