I was torn when I read your list the first time. For one, I don't think the Swarmlord and Carnifex's are worth the 280 / 190 / 190 you're spending. I'd take one out, take a Trygons or a Malwoc instead (don't come in the center, but on the flanks to distract and stay alive), and use the point costs from the other to pay for a few Tyrant guards for your Swarmlord. Also, the imo tervigons have too many upgrades (it also needs to say Troops instead of HQ by their names considering you're bringing them as troops). I'd remove Onslaught, reduce Terma squads to 10 each, and you got another 150~ points to play with.
Having said all that, I'd love to see how this list does in combat. I don't play Carnis much but I could be completely wrong about their point efficiency.