Billmen

What is their best application?

They are like a cross between spearmen and Swordsmen. Basically charge them into anything but don't let them take a calv charge. Also, they are very anti armor.

in my dictionary, the Billmen are a special species, can be found along a special species called "longbowmen". they are usually dull-gray in appearance, and like to swim along the forests of stakes or the narrow ridges of stonewall. they are slow but have a nasty bite. however if hits by cavalry outside their normal environment, they tends to cry a bit and then died, due to a disease called "MTW2 bug".

You could look here https://forums.totalwar.org/vb/showthread.php?t=86775

They're great against infantry. I use them with Spearmen and longbowmen to much success!

I use Billmen as a cheaper alternative to cavalry (mostly in the flanking maneuver tactic on the frontline fighting)