Hive upgrades to reduce supply cost of drones, lings, roaches and mutas.
Nerf all zerg tier 3. Make them zergy too. Limit infested terran spawn with a cooldown.
More hive upgrades to reduce cost of lings, roaches and mutas. 300/300 each, but only 30 seconds.
Make it zergy!
Balance as needed. Test separately before implementation.