Right now when you hit a unit it looks like he just got a hiccup and continue like nothing happened until he eventually drops because you gave him his second dose...
We really need some kind of transition...something that tells you "yes it seems he's been hit by your bullet and he's not in a good shape anymore" ;-)
Make it fall or something and then decrease drastically it's ability to return accurate fire please.
Depending on the severity of the injury he/we should immediately loose consciousness and die shortly after if not patched up.
Cheers