Twenty families and a village. Set up the country and the enemy, then raise a settlement, an army, and take their village.
The same seed, style and size give the same country again.
Independent villages between you; each pays whoever holds it and watches the country round about.
The most people either side may have — villagers, soldiers and recruits together — however much housing they raise. A lower cap means smaller armies and a faster game on a modest machine.
Stone bridges over each river. Leftmost leaves it to the map style; none at all makes the river a wall with only the fords through it.
Shallows a column can wade, slowly and without cover. Every river keeps at least one crossing: a river with no bridge always has a ford.
Farms need fertile land; lumber camps a wood; mines and the foundry a seam in the hills. Resource works may stand any distance from the village.
The field manual has the Conquest keys and the finer rules.