The AoE near the end can get pretty cheesy since it can interrupt and paralyze, locking out healing and buff recasts. But it was that way with the last 160 boss as well, and the same strategy works: save up a few SB bars and nuke down the boss at the end. And yes a Wall and a Boostga are a must. Thankfully finding a Tyro with SG or an OK with Vessel seemed pretty easy.
I've personally been rocking my Luneth with his BSB + Thancred's Air Knives and the dagger boosting RM, adds up to a lot even without considering Vessel/Shout, and sometimes I even sneak in Dark Bargain. As long as I have a bar back when enWind is still upi t's pretty easy to stack his stuff up to do 9999x8 with interrupt if the boss doesn't resist it.
Yshtola is my backline, she has synergy and all 3 of her released SBs so i can pick whatever is needed. SS2 is great but I've used Aetherial Pulse quite a few times when paired up with a Tyro or Twintola and even Medica 2 once or twice. If there's no healing to be done, I can just use Wrath and catch the Wall refresh early or keep Medica 2 on standby.
I'd almost complain cause my Yshtola is so strong I never get to realistically use my other good healers in MP (my Relm has all of her SBs sans BSB, Eiko and Selphie and Vanille and Arc and Aerith all have 2-3 as well), but really, she has saved so many mediocre pugs at this point I'm not even mad anymore. Luneth is just fun to juggle his buffs, though I have used PCecil, Beatrix and Thancred too.
Edit: I actually pug'd 140 pretty comfortably with no Boostga/Hastega just now. Over half the raid members had BSBs though lol.