Please just read the last part if you don't feel like wasting time with hardly-relevant and unimportant words.

Hi, just want to ask about the red/aggressive salamander's barrel explosion. I went to Sinasoka today for the salamanders in Mia's vanguard squad, and I was quite shocked when the first red salamander I encountered blew away about 5000 health of Mirel alone. I tried it again a few times, and the listed damage ( always around 1500 ) doesn't really match the actual damage Mirel received. (6021 Max health before hit - always around 930 left after.)   Even with Mirel taking 200% fire element damage, that still doesn't really add up.  

Then I tried letting Mirel guard and let Ryen explode the barrel, the damage listed is almost exactly the same (still 1531) but Mirel now is left with around 2700 health.  And I paid some attention to the health of other party members, namely Ryen, Chiyo and Mira, who all have verying degrees of fire resistance. (probably due to their equipment) Ryen took about 2500 actual damage in place of (listed)1600, Chiyo about 1600 in place of, well, 1000 I think? Mira 2500 in place of 1800. Basically none of them actually loses their health accordingly. 

So the question is: Does the Barrel Explosion actually deal damage according to Max health or does the damage count twice? I'm sorry for being so drawn-out (and for any possible errors in my expressions - I don't usually speak english.)  but I wanted to be as clear as possible, so, yeah.