[Chaff]

I like the idea of an ENG deploying a field turret AND somehow adding (the same ENG, or other/additional ENG(s) some cover or protection for it.

A small Outfit could deploy 4 of these on the downside (out of sight) of a hill (on a road or major route thru the terrain), lay out a mine filed, and throw havoc on an enemy supply line for several minutes. Destroy vehicles and kill some enemies. Pack up, and set up house at another strategic choke point. Done wisely, a small group of engies could really frustrate and slow an enemy down.

If an opposing empire was moving significant amounts of troops and resources by air, deployable AA field turrets on high points in the terrain along the primary air route(s) could also slow down the enemy.