A lot of realms were almost armies in themselves, run by a single person who issued every order and got everyone to the place they needed to be.
In my experience, the armies were not usually run by a single player, but by a council. Typically anywhere from 10 to 20 characters would debate orders, and then issue a common set of orders to the entire realm. That was back when we had duchy armies (or battlegroups for you fossils), that pretty much no one used. That, and the communist tax systems, made for some killer war machines.
