HECUs may can be killed by one shoot on fatal parts of body,you too,if you have not battery in HEV. Damage of explosives are very scary,range.The explosion wave just touch you,then it can cause seriously hurt. If closer little, you will don't even have body. Bullets damage(look up from internet):SPAS-12<MP5<Beretta<DesertEagle<M16
'Realism' isn't Sven Coop's strong suit.
Because it's a game designed for more than one player. You can kill grunts easily if you do it carefully w/o rushing into them like a mad. Also most maps have their own skill settings for monsters (in mapname_skl file OR hard coded in map itself), so this script won't work in most cases. In other case there are some non-official maps (just a few in official) that really sucks at balance, they made grunts op because authors expected maps to be played by even more players (like 10). Sven Co-op is not a game for pussies- it requires some skill training. The better solution could be sometimes adding starting suit to map configuration file, but you will need to do it for EVERY map you play. Suit (armor) points greatly protecting you from damage, it's more durable than health, and I usually spawn it when playing map with only one or two partners.
A good skill,used in 1 map.