Grenade Launchers

[Imp]

Use is diffrent to MGs in my opinion due to low ammo capacity.
You can use them with range turned down to half behind squads like MGs or if have HEAT & hence capability vs light vehicles send with scouts to give defence vs.
But the main use is to get a battle over quickly which normaly means less casulties for you. The Russian idea of a platoon of 6 supports this if your game is big enough to purchase them. I use pretty much as direct fire arty, main goal is to suppress & let the attack commence. You then need to pull them out & reload, ammo containers are not that usefull for this takes 3 turns use trucks/carriers.
Use them vs units in good cover trees buildings rough dug in & leave open spaces & slowing advances to your MGs. I often prevent them opfiring if safe to do so to they are an attack primer & use of often allows taxis to stick there noses out & add their firepower in relative safety. Now you can attack & move on.
This platoon is also handy when you discover ATGMs which are often located in good defensive terrain so having them trail your armour works well to keep the attack going forward.
Its a case of right weapon for the job its not a MG but can fill its role if it has to, but not for long.