Terra Arma's military doesn't exist, formally. No taxes go to defense, no soldiers are conscripted, nobody stands at walls looking with bored eyes at the country side. In this sense, Terra Arma has a true militia.
In times of crises, battle, guerra santa or other conflicts, the militia simply appears as needed. Groups of men, women, and often children simply grab their weapons, throw supplies on the war carts, and get swept away with the mob. Of course this makes the militia hard to number, but puts the maximum amount of troops at "Everyone". Generally, half the population at most leaves to battle, the rest staying behind to defend the land and keep it running. At the very least, you can get a ten-thousand strong group simply screaming nonsense about injustice, the gods, proving strength, and getting real combat experience.
The group, as mentioned before, has no military hierarchy. Nobody tells anyone else where to attack, where to stand, where to dig in for the night. The group simply follows a kind of hive mind similar to that of a moving riot. Someone starts setting up a camp because they are tired. So is everyone else, so this is where we are setting up camp. The south wall has a gate on it, so everyone starts rushing it. Someone chops down a tree to use as a battering ram, and men swarm to it like ants thinking that is a brilliant idea. Sometimes someone walks ahead to act as a scout, sometimes the whole group just shows up to see what is going on.
The real strength of the Terra Arma militia is in its troops: Their skill and number. The soldiers train with weapons since they are old enough to hold one, making them incredible combatants who know there way around multiple weapons. The average militia man has much more combat training than the conscripts, and most of the time full-fledged soldiers, of other nations. When the form a mob, even well placed and well trained troops can't fight off the mass of flesh and weapons.
As for the individual troop, everyone arms themselves, leading to a massive difference in tactics between even parts of the mop. Many weapon making techniques are known by this country, and more are added to the weapon lists every day. Halberd, pikes, longsword, spears, maces, mauls, military forks, war hammers, war scythes, arbalest, crossbows, slings, flails, axes...every weapon that they can think of is found in some part of the massive war mob, even the smallest containing at least one example of each. Even more exotic weapons like to show up from time to time, often created by the soldier wielding it. This is especially the case with Weapon Priests, who go through a rite of making their own weapon with imbued with subtle magic.
That isn't to say they don't have larger weapons, and in fact love their artillery. The artillery generally is lifted along with the supply carts spaced at random places in the mob while it is on the move, being pushed by dozens of men who switch whenever one gets tired. Often, the artillery piece is owned and managed by a single family, who will gladly maintain and fire it with pride. They often switch out who joins the front line mob and who gets to fire the big bows. Catapults, often armed with lead taken from the mountain, have several different kinds of shot. Along with normal balls several meters wide, they also have a small group tied together with string that is fired on enemy positions, in order to injure troops. Several collapsible and delicate siege towers exist, usually as a means of getting a cross walls. Ballista are also in use, though in smaller number due to how the tactics work.
The Weapons Priest should also get special mention. While they join the mob indistinguishable from anyone else, they provide useful services that are not often apparent at first glance. They are capable medics, performing first aid and emergency operations after a battle has decided. They also know a little magic, often helping the battle in subtle ways, such as heating up catapult shot before it is fired on the dry walls of the enemy's palisade. Typically, they have even more skill than the average soldier, and can often be found in the heart of battle cleaving a way through the enemy.
Of course, being in close proximity to the river means it must often be crossed. Terra Arma is in possession of several large rafts-slow moving, poorly defended vehicals that let the supplies and men cross the river. In times if peace, they are used for trade, making this well known.
After a battle when we have control over the field, assuming more pressing matters are not at hand, everyone scavenges over the field. The bodies of our fallen are collected by the mob, and buried with their favorite weapon in a suitable location. All their other weapons are collected, and given as an offering to the church, who in turn gives them to the weaponless. The enemy weapons are also taken and donated to the church, with the bodies left for the enemy to take care of themselves. If that isn't possible, they are buried under our own customs, with their side arms. If we find a weapon that is particularly interesting, we send either an injured but still standing or the youngest militiaman back home with it, so it can be studied and replicated.
I can write more, if I didn't win....