I have weapons for fighting long range. I have skills for fighting long range. I have PAs for long range.
But when I try to stay long range to attack, mostly bosses, the AIs just crowd around me.
Maybe you wanted to stop people just using the AIs to win? But this makes it impossible to actually be a long range player and use AIs.
I'm not going to sit next to the enemies and waste all the things I have for long range just so the AIs can fight.
Use a better method than just "proximity". If there's a single boss and there's me and 3 AIs, and I'm hitting it, they should be hitting it too. If I'm actively engaged with enemies, shouldn't that be enough to say to the AIs ... "Hey they aren't just a lazy bum who wants us to do all the work" ?