The fact that you are playing a 3v3 means that auras will be more important then any single active skill. Carrion swarm is one of the most underpowered skills in the game currently, the damage cap is bad enough for 1v1s let alone 3v3s, this skill won't have a huge impact in large team games. Sleep is always annoying and given the lag from large battles can be very hard to stop. It also neutralises those annoying ultimates such as starfall.
If i was using a solo DL in a team game i would probably just go ghouls --> gargs and let an ally get the heavy air. Wyrms are a possibility in a long game as well but require a lot of resources/time and don't benefit from any of the DLs abilities. You can always get aboms against a ground army, aboms and banshees works as ams effectively adds 600 hp to aboms against heavy air (it blocks 300 reguardless of armor types) giving more time for you to kill the ground ranged units while your allies anti air can take care of the heavy air.