The level 43 requiredment in 200 super effective charged attacks is the death of me. As someone only fighting the grunts, it is literally a guessing game in which if the mons I brought can hit any of their specific mons super effectively, or even do it before the opponent gets knocked out by the fast move. And some like the Ground specialists are especially fucking impossible because there are that many type combinations with Ground in it. There are a gazillion times where I fought the grunts and never progressed the requirement because of that.
I normally dislike fighting gyms, but I might have to do that now just so that I can finally be clear of that monstrously irritating requirement.
Edit: Okay I looked it up, it turns out training with team leaders do count towards this goal. Beforehand I assumed it didn't, and I really wished I knew that before.