I built 3 epiteichismata buildings in a region, costing a total of 9 infrastructure per turn. I don't feel I need them in the region any longer. There was no indication that they were unremovable.

How do I remove them?

First game ever, playing as Messalia, with the new DLC. I've noticed that when I dock my fleet, and then hover over the settlement, the fleet is listed as part of the garrison; along with any garrisoned armies. Does this mean that my fleet's crewmen will help if the settlement is besieged by land (T...