A comprehensive mobile base defense solution:
Introducing the Mallet:

A tank built to house a variety of turrets, able to anchor on the go to recharge its batteries (during the day at least)
In the above picture, it's equipped with a Praetorian Ground Defense Turret:

turns a bit slow, though it more than makes up for it with its firepower - the brick's shields go down in 10 seconds ish
Main drawback to this is the graphics: they made wheels add dirt tracks in the new update: constantly seeing tracks floating in the air is ... somewhat unappealing
Edit: Oh, and feel free to add me to the kingdom

Edit: Turret tends to have trouble when in hilly areas - modifications underway