Instead of nerfing turrets I think the game just needs proper AI (no small feat I know). Get meelee dudes to hang back while ranged units kill off your turrets, or if your base is heavily defended with one small opening and a dozen turrets pointing at it, hang back and starve you out/use mortars. I have no idea of the design side of implementing that but anything except rushing into your base to commit suicide on your turret bombs would be an improvement.
Even just having meelee guys ignore turrets would make things more difficult IMO.
Even just having meelee guys ignore turrets would make things more difficult IMO.