Let me explain. The frag RPG launcher is currently useless because you can only fire ONE round at a time. But what happens when you can fire TWO rounds at a time? Suddenly it's low dmg wider AOE infantry hurty power becomes actually usable and pretty useful.
I propose giving the frag launcher a two round chamber firing thingy that lets it fire at a faster RoF than the head and tandem rockets. Make it's overall RoF faster, but its reload time slower to compensate. Give it 4 rounds total (so 2 loaded when spawned in, two in the reserves) so you get one reload out of it.
Not only would this change balance the frag RPG better, but it would make it more unique amongst the RPGs.