Originally Posted by
Fwahm
That's my entire point; when you're using Seigan or don't have capped magical haste, it could sometimes be useful to have Arke gear's greater haste available when tanking for whatever reason; gearswap isn't going to solve the problem if you don't have the gear in the first place.
As someone who regularly joins shouts for things like Omen Caturae, Reisenjima T3s, and VD Ambuscade, as well as soloing stuff that trusts sometimes can't keep up in healing unless you're sitting in DT gear (hi Crom Dubh and Oryx), dealing with non-optimal party setups is a fact of life for me, and Seigan is often a lifesaver if the tank goes down; without Seigan, Kyou will disable you twice as fast with his enstatuses, and Fu can just kill you with a bad double attack + TP, even in max DT.
It's very common for pickup groups to be me, BLU, GEO, COR, WHM, tank, and the Geo often isn't going to use a bubble on Haste when one of the melees doesn't need it and the other melee only badly needs it if they're undercapping on gear haste/using Seigan.