TBF, I think you have the Murillo situation backwards - he was benched for being a problem, he didn't become a problem because he was benched. Sims almost certainly went back because of Covid and nothing else.
Say what you will about Murillo, but when a guy is a star before Armas, then becomes a star right after Armas, and wasn't injured or anything during Arma's tenure, it's fair to say Armas had a lot to do with him not playing up to potential. And still he was 10 times better than Buck. Sims was just another example of benching a player who is clearly superior. Sure, Covid had a lot to do with departure, but being a back-up and barely playing on RB in MLS I don't think helped when alternative is back-up in EPL. Again, be it as it may, that's two example of clearly superior players whom Armas benched and left.
Kaku started to get similar treatment, so I definitely prefer Bradley to Armas, so that we don't risk losing Kaku as well, but we need someone better to coach this team, since it looks now even worse than under Armas with 5 defenders and no midfield.