Lets remember that to an upgraded conscript beat a lmg gren they MUST be in cover which synergies very well with their kit of sandbags and tripwire mines, even molotovs. Otherwise is almost impossible conscripts to win the matchup without spending munitions.
BUT
I would nerf it from 50% to 35% and should be enough.
This synergy is what conscripts lacked for years.
MY QUESTION IS
Do they keep the bonus if merged with other units?
It is a squad ability and not an entity ability so no.