>>535468312
Yep, really. What you might be seeing is the fact that if people can't Guard a MCH LB, they'll sometimes buffer it right away with Recuperate. If they're BH5 (more healing), a single Recup will negate a lot of the incoming damage as long as the MCH LB doesn't kill them outright.
Remember also that some casters have instant panic buttons even when Guard isn't available, like Forte on RDM or SMN's shield, which will block a huge chunk of the LB's damage.
If you're looking for the big squish, AST is the easiest target based on the current Frontline modifiers since WHMs can have shields. And yes, I have to track this myself since this game is poorly documented enough that this information doesn't exist, or isn't reliable, elsewhere.
This also helps to explain why you don't die on VPR at the moment!