I like the idea of bringing SMGs in as primaries. High RoF, low impact. Basically the HardLight, Atheons Epilogue and Necrochasm, just...call then SMGs as they are. And grenade launchers as heavies. Lower damage and aoe than rockets but higher RoF, arcing projectiles, perks like "cluster bomb - splits into multiple smaller projectiles" and "concuss - stuns enemies within range" and etc. They would fit perfectly into the gap between rockets and LMGs.