There's such a thing call phases.

Garuda EX for instance: the key phase is the tornado phase. It's the wipe-able phase and the hard phase. If you have an LB and use it on the eye phase, you better well be sure she dies. If not you just derped and might have wiped the PT.

Saving that LB to the tornado phase, and LBing suprana/chirada makes all the mistakes in that phase, easier, and then you can push it to the next eye phase which is where you finisher her.

Spamming LBs usually costs runs because people forget the mechanics are there for a reason.