I typically have a build, with variations, that follows these basics:
1) Bowman: I have at least two or three archers who carry two-handers or spears as back-up weapons. I also have two crossbowmen who carry halberds (pikes or billhooks) in the same fashion; this allows them to support the front line once the bows aren’t viable.
2) Shieldwall: I insist on having at least three hoplites (spears with shields), using any secondary variation that suits them. It basically forces the enemy line to take damage repeatedly or expose themselves to more arrow fire if they choose go the “long way” around my own front line.
3) Between spearmen: I keep “men-at-arms” who can swap between hand-weapons — swords, maces, axes, or hammers, depending on if the enemy has shields or heavy mail — to charge out once the shield wall is compromised. This provides the additional raw damage that assists my bowman and primary spearman. Also, I give them throwing weapons — javelins and nets — to cover mid-range fighting.
4) Heavy-handers: At least two of my men should have great axes or greatswords on the group’s flanks. This way, if the enemy makes it en masse around the spearwall, they will be weakened by arrow fire, and I can have the two-handers clear out the weakened troops. This is opposed to early builds that had two-handers in the middle — I find it’s actually better to have them on the flanks.
5) Finally, the minutia: usually one of my billmen is a hound-master and I’ll pick one other character who has high fatigue to have a hound as well. At least one “man-at-arms” will have a myriad of secondary weapons and another will keep nets and more “specialist” weapons. This allows me to keep a balanced group that can improvise against unusual attackers. The archers focus on utility and offense while the two-handers on offense and max fatigue. The frontlines emphasize defense, naturally. So far the build has worked well for me.