I personally can’t stand the small Shattered Realm room; I don’t know if it’s a factor of controller use or not, but even with attempting the camera angle to reduce boss aggro, once one boss approaches the player, being anywhere near it causes the other bosses to aggro and the whole thing becomes a giant fiasco. At least the large SR room allows you to kite and focus on the boss you think is the greatest threat - the small SR room doesn’t allow for that at all.
That being said, I want to bring up a topic on what you think is the hardest combination of bosses for your builds. I think some of the Boss-level enemies in SR65 can be a lot tougher than actual Nemesis level enemies, and in some cases, some bosses have multiple components to them, making the challenge even harder. Stuff like bosses that trap you with bosses with mega-nukes, bosses that require you to kite alongside those that are constantly harassing you. That sort of thing.
Some combinations I can think of:
The Sentinel + Kaisan = having two crystals that buff all the enemies around them, and I find SR Sentinel without the favor of Crucible buffs to be extremely challenging.
Salthazar (the poison Basilisk boss) + Grava is cancer for melee builds.
Mostly play ranged so anything involving MQ + another boss aggroing immediately is just awful. Flip side, grava isn’t nearly as frustrating on ranged.
Was actually getting gang banged by a suspiciously geared Fabius + Benji the other night. Lot of imprisoned SS one shots before I could finally get one of them down. Fabius can be anywhere from a pushover to fuck this noise depending on his gear and aggro partners
I never turn the camera and I believe it is just random. Sometimes as soon as you enter the small arena two boss immediately aggro. Other times, only one, but on those other times if that aggro is a caster who won’t come to you then you have no choice but to aggro others too.
I also detest the small room with a passion. I play a little zoomed in and in the small room I can’t even see anything at the default angle, just stone wall.
Besides the more difficult ones already mentioned, I find Tigran to be pretty annoying with those physical/cold shotgunning ice bombs. I imagine Ramzul would be scary at high SR if it can spawn.