Limit Break an important part of the frontlines and also helps the game flow. Can be the only way of breaking through a defense that you been unable to breach for the whole fight. Ive seen white mages run in and swift cast holy at the same time a black mage uses the lv2 limit break followed by another black mage using inferno wiping out 10+ people in 3 seconds that you couldnt get rid of in 10 minutes. I think LB works as it should.