Having turrets at your base automatically built is a bad idea I think. It takes a lot of option and strategy off the table for players. What was great about them in Halo Wars 1 was the decision you needed to make of whether you should invest valuable supplies in them, especially early in the game, to defend against leader and warthog rushes. Or should you risk putting all your supplies into base upgrades and units when a prophet who can strike anytime lurks on the other side of the map? What if I’m playing covenant and want to leader rush a base? If my scout shows no turrets I may make the choice and take the risk to attack. But now, automatically my leaders/units are going to start taking damage before they even touch the enemy base, thus less strategy for players to use again.
I’m hoping this is just a thing for Domination, and will be different in Deathmatch.