leafbarrett
Better than he thinks
Has there even been a situation in the past where the problem was an entire team being broken?"If you have more than 4 Baton Passers you cannot use Ingrain or Stored Power (this would allow Magic Bounce to stop phasing but encourages skillful play on both sides. Since wrongly switching Espeon into Skarmory or Hippowdons physical attacks from the start will quickly tip the favor towards the stall team)."
Except that even for a complex ban this is ridiculous, Our only complex ban before was Drizzle+Swift swim. After seeing your signature, You'd have to make ONE complex ban work like three and that is definitely asking for too much. If 3 baton passers will kill the chain passing/Defensive passing of Baton pass then so be it but the truth is, Defensive passing is a solid playstyle that has very few counters that don't absolutely cripple yourself and even then most of these can be manageable by smart plays as you yourself suggested with Mold Breaker Mega Gyarados's Roar can go through Baton Pass but I'm pretty sure it doesn't negate ingrain. Haze Quagsire isn't an auto counter to BP either as the sheer power of Stored power along with a few boosts can kill Quagsire before it hazes and just sweep the rest of your team with it. Three Baton passers limit this greatly and it'll be more manageable but still alive and not as powerful as it already is, With 3 Baton passes in Scolipede, Smearlge and Vaporeon, you can get up to +4 in every stat (except attack and maybe Sp. Att) with an ingrain with good playing and then set up Espeon as your win condition with Sub, Stored Power, and any other moves you think you might need. This greatly balances it and makes more and more pokemon effective against them.
I'm personally pro-nerf, specifically of the user cap variety. 3 seems like a reasonable cap to me, though I guess 4 isn't out of the question. 2 is kinda pushing it a bit far with the nerfbat, and 5 is basically pointless.