Greetings, alockwood1 ~
I believe you have answered your question in fine fashion. A soldier may sometimes wonder about his enemy soldiers while back at base camp, but, once the shooting starts, he just wants to survive and that means killing the enemy before he kills you (or your buddies). Any enemy soldiers who survive and get away can come another day to try again to kill you. You don't regret the ones you kill, only those that escaped. That is the nature of war.
For a sniper, the killing is more personal in that you see their faces through the scope while aiming. Still these targets are usually high-profile enemy leaders that may make decisions that may kill numerous of your side's soldiers. Why would you regret killing them?
You overuse commas! You need to thin the herd a bit throughout. [ ] = delete
soldier’s mind, as I’ve never worn the uniform[,] or been in combat[,] or any of those things. OR soldier’s mind, as I’ve never worn the uniform, [or] been in combat, or any of those things.
some of them have passed away[,] and are
who is recovering from a knife wound[,] and (who) was just released
So, when he gets into combat[,] and gets an enemy combatant
He isn’t thinking about if the guy has a family, [or that](if) he is a good artist, or anything (else).
has a weapon[,] and that it might be aimed
today, next week[,] that enemy soldier ... civilian personnel[,]and kill several of them
has to pull the trigger[,] and kill the man
Cheers!
Harry