A RK with DD/Heal equip might come handy. Reason:
Azbauz and Maugrush. The most dangerous thing is the bleed that Azbauz puts on the tank. One healer often cannot outheal it at T3+, a RK as second healer spamming HoTs on the tank changes that. (Cappys can use SoD / LS to carry themselves through the first two bleeds, Guard has WH, which may not be enough for one bleed.
) Fight will take a bit longer ofc.
Shatarkha. We like to put DNF on the person that gets iced, so we do not have to waste a rez. Healing usually isn't as crucial as at boss 1, but he should be debuffed at all times, else his horn blow will kill some group members.
Groz-and-Ulk - compsition doesn't matter. Designate an interrupt order, that is all what it takes.
Why is that? We usually completely ignore the ice block, and rez/DNF the char when he/she is killed. This is the fastest way to bring him/her back into the game. Or does the ice block some kind oy damage/debuff to your group?