A tournament is not necessary, at least for me. I think it would be between Bowsertree and DOSV for #1. I'd go with Bowsertree because he can counter any character. DOSV has a great fox/falco and a good samus. Hat gets honorable mention. Right now I can't beat Bowsertree's samus, and I don't think I'd beat DOSV's fox/falco in a set. Hat's sheik would beat my marth/fox in a set as well. Therefore, I'm at least #4. I haven't played EE for who knows how long, so I can't comment on him. But #12 in teams with G-reg? Come on EE
No tournament is necessary. I'd bet everyone could say whether they'd win or lose in a set against anyone else's character like I just did.
Edit: and I forgot about Frozen.