Yeah, the bard lb being a healer one is stupid. Lbs in general are pretty poorly thought out.
It would have been better if they took a Dynasty Warriors approach and every class had a unique offensive LB and they gave each person their own. And in order for it to be a lvl 3 LB every person would have to use theirs at the same time, making it a single giant LB.

Anyway the tank one is useless so you'll probably never see it. Healer ones are typically only used in HM primal fights.