i'm probably a bit biased against bronzong because i think it's worthless but i do realize its immunity to EQ makes it a better check than forretress
skarm often carries toxic in ubers so it's definitely more of a counter than a check
this gengar argument is ridiculous and i'm satsified with leaving gengar as some sort situational check or just not mentioning it at all
the fighting arceus set i'm actually getting at is 240 hp 252 spa 16 spe modest which i used as my extremekiller check for a few teams. so you can just mention that fighting areus is a good check but needs bulk and maximum special attack to be reliable.
i do take your point about obscure checks so i do think it should stop here
don't mention sableye it's shit
forretress should have pain split as a primary option but that's another story entirely (another update for me to get onto)
edit: you need to pair physically defensive ho-oh with gira-o/a or ghost arceus with roar or WoW to beat arceus. that ho-oh's main purpose is to take one extremespeed and attempt to burn it then switch out to something else that can handle burned arceus.