Limit breaks should all do the same damage

[Edellis]

There are plenty of situations. Your party just has to know them o.o

Any dungeon situation where you can pull a massive amount of mobs, i'd prefer the tank grab as many as possible, and the BRD/BLM just nuke them. It's way better than a measly 4k-ish single target damage to a boss. Especially since most melees (for SOME reason) don't decide to LB the boss until it's at 2% and 50% of the LB's damage will be lost.

And in many fights, unless you're struggling, bosses die way before you can even get LB2.

tl;dr different damage on LBs allows different levels of usage. AoE limit break has plenty of valid usage outside Ifrit EX. It's all over coil and the dungeons.