It's weird that this person assumes anthro pokemon are inherently weaker than feral ones.

I mean Meowth was kind of proof of that he may be weaker because of his more human like intelligence and struggles with being a strong as a more feral Pokemon.

That was more because he never fought, and one case just isn't proof.
Also I don't count Meowth as an anthro.

That's why the fourth category is there for a reason just think about it having someone that is training you to get stronger even if it's a 10 year old kid it's more beneficial than you going at it alone plus they might have disc that you would need to improve your skills then what you could do naturally.
Not every Pokemon can live up to the standards of Mewtwo after all there's anthro Alakazam out there at least 50 times smarter than Mewtwo feral or anthro when it comes to IQ I'm being very generous with Mewtwo here but take it upon themselves they're most likely just be a really good accountant then anything living up to greatness on their own.
Plus I like to think because more anthros are more society based they don't have those feral instincts to go all out like standard Pokemon will so you can say maybe anthro's holding back and has not cut loose cuz they have self restraint.
But yeah they're still Pokemon at the end of the day so you would think pokeballs at least the master ball would work on them.