What Fetterman is having to deal with is not just the problem understanding and talking brought on by his stroke.
He had to check himself into a treatment facility right after winning the election for depression and who know what else. We only get the parts of the story they want us to know.
As for his mental capacity, listening to and understanding what others say is an integral part of his job. He has to hear what members of the Senate, witnesses in hearings, and speakers at events say. If he needs assistance in every part of that, then we might as well have his assistant serve as Senator.
Also, how do we know the assistants are feeding him the true "rephrasing" of what's being said? Just like in the game of telephone, meanings and nuances can be lost in translation unintentionally. Worst case, they can intentionally give him a different version of what was said to manipulate him.
Then there's the whole attire issue. Who chooses wardrobe as the sword to fall on when they are providing so many other reasons to be expelled or recalled?
He's a joke. He's the embodiment of the belief that you really can vote for a glass of water for Congress, because the voting is all in lock-step with their party 98% of the time. Might as well just have one person from each party in the House and Senate for all the good voting does. Think of all the money we'd save.