I don't know if that would necessarily help. Grenade round goes off, damages 10 friendly units, and because of the target limit, doesn't damage the one enemy unit within range.
I think the idea of the grenade launcher unit is interesting, but without some greater firing controls, or better ability to micromanage them (which chris has stated he opposes forced micromanagement) I don't think the grenade launcher will be used by anyone more than once. All other AOE ships do not do friendly fire damage. Beam frigates have a much longer range, and are in general more effective at taking out masses of enemy ships.
I've even tried to use grenade launchers on defence, they occasionally work well against ships that are tractored, but are very dangerous against ships like raiders who ignore tractor beams, and fly so fast that the grenades may take 20 seconds or more to actually connect. You will never know what the target is next to 20 seconds from now, you just have to hope they aren't right next to your command station, or power plants.
The difficulty of preventing friendly fire, and the ridiculously high energy of each ship (400) makes them not worth the effort 95% of the time.