I came up with a small analysis on the roster.
Alright, so this was the roster we saw for sure. Below are confirmed characters not included.
Added them into it, and then considered the most obvious returning veterans.
Here's what we basically predict. Then, I add the questionable characters: Lucas, Wolf, Snake, R.O.B. and Mewtwo.
Add in some Sal Romano, I noticed that there was a strange build then. To be safe, I added one more row of 3, one being a random button.
I then considered what was left: A Metroid, a DK and an unknown. Ridley and K. Rool, and for the sake of the argument, Takamaru.
Not too bad of a roster.