I was watching a guild member in a pug group of roughly all i410 people and … the fight was pretty simple. Get hit up on the ledge, group them up, AoE them all down, rinse-repeat, collect loot.
But for the actual iLevel this boss is designed for (mid-390’ish) … we can’t seem to put out enough dps to kill these adds fast enough.
What is the trick to the mobs on the ledge?
Or is the solution really to farm M+ until you’re 405-410 and come back for your sweet i402 loot. 
The trick is to see who isn’t actually swapping to adds.
I haven’t checked logs or anything but I have to assume they are.
My only guess is people didn’t switch to an AoE spec, and are trying to ST the adds down.
we only have one mythic boss kill ever and we kill Dathea every week no problem.
took a few pulls to learn but it’s not bad.
you have to sandbag some cooldowns and ruin your parse so you can burst adds though. Some are not that capable.
Yeah we told people to save CDs. It’s the crux of the fight. Dathea is a non-issue.
The only thing I can think of is people aren’t in their AoE spec.
Cause with an average iLevel in the mid 390s, these adds should MELT.
it’s also a two-group balance so… making sure both groups are about equally strong is important too.
behind Dathea is a much harder boss in terms of split dps and single-aoe-single-aoe coordination.
and behind broodmother is an even harder boss, also including aoe elements, although not as signifficantly.
one that I killed tonight… BOOM!
but pug… we took i think 2-3 days to kill Dathea, and maybe two resets to kill Broodmother. That might be the end of the pugs at current ilvl.
I mean we 2-shot Grimtotem if that’s one of the one’s you mean.
All we have left is Dathea and Broodkeeper.
and Raz. dont forget the big one.
Raz doesn’t count, it’s a lol-overtuned fight. worry about that later. 
We’ll probably do what 95% of other guilds do and begin Mythic, gear up, and come back to Raza.
Which… is a flipping stupid design, imo.
More stats are always going to be a big help. Yes if everybody in your raid group is ilvl 390 and you’re at the skill level where you’re going to be killing heroic Dathea, you could probably stand to do some keys. You would get some gear, valor and score (to unlock valor upgrades) and have more ilvl for the raid.
it’s not overtuned but it is tight, it’s just demanding on execution. if your dps is averaging about 70k or so, and doesn’t die along the way, you’re good.
A prot paladin or any dk does really good on those platforms. I’d recommend using one of those.