Mercenary Longbowmen are mercenary archers available to Brittany, Burgundy, and Guelders. They have high melee armor and no minumum range, allowing them to stand and fight when charged, a situation when most other ranged units would rout.
Unit Statistics
Vital
Available to: Brittany (with English Alliance), Burgundy (with English Alliance), Guelders
Trained at: Archery Guild
Century: 15th
Cost: 75 Florins
Combat
HP: 45
Attack: 7
Armor/Pierce Armor: 3/0
Range: 7
Special: +2 vs. spearmen.
Commentary/Strategy
Mercenary Longbowmen are pretty decent fighters, but what really makes them stand out is their ability to fire in the face of certain death--that is, if they're being attacked at close range. They also have very good melee armor and have pretty good range for a bowman.
The downside? Cost may be rather trivial with a good economy, but this notwithstanding, the disadvantages are more situational. Brittany has to give up Genoese Crossbowmen and better knights to use these--and they have good archers anyway. (Especially their mounted ones.) Burgundy would have to give up their Flemish mercenaries, though having a strong archer might outweigh this. And Guelders, although they receive this outright, has very durable (if slower) arbalesters.
Using this, then, depends on your civ. A Breton may not use this that often. A Burgundian will probably benefit the most from this, because they have bad archers, but the silver situation is a bit tricky. Guelders could use this as sort of a faster foot archer, but they too receive mounties. The best use for these would be for holding a position at all costs, since they won't buckle if the cavalry come.