Physical range Lb is slightly weaker but it Casts faster. I remember, well a theory since im not sure it was tested, but aoe lb priority should be smn, Brd/mch, blm when there are only about 2 (maybe 3) enemies. A blm can do more damage than the damage difference with the time saved from the long cast. Even more enemies then smn, blm, brd/mch. At this point the a caster lb does much more damage than what a single blm fire4 could do