Maxed endurance dwellers again

So, i'm nearing an entire vault full of super soldiers all levelled with max endurance and a +7 suit. it's taken quite some time.

I'm still noticing health bar differences in the dwellers in the first two rooms when attacked by deathclaws. Both vault door guards are wearing +7 E and are rocking identical damage pets and weapons (MIRV) but every deathclaw attack sees one of them on slightly lower health. Both should be on maximum HP. Does anyone have any idea what's going on?