Oh hey, that is my local scene's monthly.
I do think Metaknight could fight at least Sheik and Rosalina 50:50 without customs. Not too sure on Sonic, but I can only imagine he'd have a much better time than Bowser. Metaknight also has a very bait heavy playstyle which would suit you, but unlike Mewtwo and Bowser he can escape much easier from bad situations thanks to multiple jumps + his specials, and he has a great 50/50 game similar to Captain Falcon where you have to guess between a dash attack or a grab.
A DK main I know picked up Metaknight strictly for the Sheik matchup in a non-customs metagame.
https://www.youtube.com/watch?v=OOge0mkKV7g
He also has a skill ceiling that I don't think I've seen anyone approach with him yet. He has a lot of combo potential even without the footstool tech.
I do think Wolf has a pretty good chance of getting in so you may be in luck!
I think part of the gaming experience is how a character "feels" in terms of the emotional state that character invokes. I like for my character to induce real terror and panic into the opponent. A feeling of helplessness. I feel like Bowser makes people feel that way when I get good reads with him. When Bowser is charging at you from across the screen, I know I find it terror-inducing.
I dont feel like Mewtwo has that effect. It drives me bonkers when people on Smashboards say Mewtwo hits like a heavy, because it is absolutely not true. He hits like your typical character. He has trouble KOing if you play him safe, so you have to take risks on a character that can't take risks. On so many occasions, I have been up a whole stock and lost a match because I need to KO someone. He just has this weird style of play that works well against characters without reflectors, where he forces people into the air due to his excellent ground game and then covers the air with his great aerial spacing game.
Then you get characters like Pikachu, Fox, Sheik, Sonic, and Captain Falcon, and the problem with these characters is Mewtwo just CANT play the ground game well against them. The reason is that they pretty much ignore Shadow Ball. They all ignore Shadow Ball for different reasons: Pikachu teleport attacks behind you. Fox has the best projectile reflector in the game. Sheik can beat Shadow Ball with the superior needles. Sonic can just run under Shadow Ball (lol). Captain Falcon is too fast to pressure.
So, against these characters, Mewtwo has to primarily rely on Dtilt. Except Dtilt isn't as good as it seems, and you can punish Mewtwo between swipes. It has a whole 20 frames of recovery, believe it or not. If the opponent gets in, you eat a lot of damage. If you get a max Dtilt poke, you get 5 damage with no guaranteed follow-up. That isn't a good economic proposition. Mewtwo's Fair is an awful poke, and his Bair basically isn't a poke. His jab has the same startup as Dtilt, and it isn't that good. Jab 2 is incredible, but the transition between Jab 1 and Jab 2 is horrendous, and I get grabbed between them all the time. Mewtwo might as well not have a Pivot Grab - it is truly atrocious. The Pivot Ftilt is solid, but you can't really get pivot space against opponents that are significantly faster than you, and the tilt has a 14 frame startup.
What we have left is Disable and Confusion, both with a lot of recovery, and Mewtwo's complete lack of offensive options. So I end up going for random short hop Nairs against these guys, because it hits a lot against people desperate to get in, and while it isn't safe, it isn't easy to punish, either. Especially if you don't play against Mewtwo a lot.
That is kind of my breakdown of why I think Mewtwo just can't win those Matchups. As sad as it makes me, I think I am going to have to pick up another character, though I will keep playing Mewtwo for matchups that I think are favorable for him.
I think the situation is fixable with frame data and hitbox changes alone, and we will see if we get some changes in the June 14th update. It feels like Sakurai put most of Mewtwo's neutral value into Shadow Ball, but he needs a plethora of safe options to work as the kind of character he is. He can't take risks or go for reads all the time like Bowser can.