This is a similar setup to what me and my guild are doing on lv85-87 mobs (most pt is lv88-89)
There is no point in having warriors with fences in as they do crap dmg and we dont fight mobs 10+ lvl higher than us (there is none..).
And who needs a lurer when all wiz gets 90% speed increase????
The usual setup: 4 wiz, 2 bards, 1 cleric, and the other varies a lot but usually a rogue, another wiz or a warrior.
We can take 2 giants pt at same time easy, 2 wiz on each, most got cleric as sub so they can bless + recovery division + healing orbit. But really its not even needed, most of the time the mob is frozen, dulled or else we just knock him back when things get too hot.
The 2 bards doing Guard Tambour + Dancing of Magic, and giving MP and speed.
And the cleric is there to be 100% sure no one would die

And for buffs.
I can understand that this pt wouldnt work on much higher lvl mobs, but at last levels its getting hard to do that (no mobs lv 98+

) and we usually aim for same levels mobs as us or so to get maximum of drops.