Yveltal does KO Pumpkaboo with Muscle Band, but with only one or two, you won't be able to stream them enough to make the prize trade even enough. Even if you were able to, I can just Target Whistle + Lysandre your Shaymins and/or Yveltals. Also saying that Joltik is a minor annoyance is pretty funny, since a basic attacker that requires one attachment and takes two prizes is far more than just that.
Against MegaMan, again they really shouldn't be able to Mega Evolve. If they do however, you're already up a Manectric EX, and can therefore Target Whistle + Lysandre it into oblivion (alongside Lysandre Shaymin). Saying that Mega Turbo allows them to Turbo Bolt if they do Mega is fair enough, but Mega Turbo is bad in the deck regardless. Why patch a matchup you'll lose anyway? It's not worth the space (and honestly never has been, people are just silly).
Entei needing to Blacksmith a lot has always been the case, but now FFB in NM is the final nail in the coffin as far as that matchup is concerned.
You only need two FFBs in NM, but with PoT this generally goes to three or even four if need be. Xerosic isn't an issue either, doing so slows you down to the point where being able to recover won't happen, regardless of the KO.
Escape Rope is only an option if Jolteon is popular enough (and it shouldn't be). You also mention N, yet fail to read that I am discussing Standard (again, I have no clue on Expanded). Regardless, you don't cripple their set up when you have an Item-based draw engine, that point is just plain wrong. I'm not saying it's broken either, it's very good, but not broken. The argument was made though that Muscle Band was better, and I was explaining just how wrong that was. Both of you have missed the main points here.