If an LB isn't used ASAP you're losing out on LB time. Also, While I'm not 100% sure on the breakdown for ranged LB, caster LB does more damage than melee on 2 or more targets, ranged is weaker but I highly doubt it's so much weaker that on 3+ targets it's not a DPS gain. So unless you used it just before LB 2 and the tank was hoping to use it on the adds in the last boss (totally not necessary) your tank was a moron.