Suggestion for New missile Unit type

I’d like ro suggest a new unit type that can be introduced to the game for all factions where appropriate. The Javelin Thrower.
The Javelin Thrower is about as primitive as it gets, before even bows, there were men throwing long pointy sticks at eachother.

The unit concept is simple:

. Skirmish Missile Infantry
. Light armour
. Poor Melee stats
. Less range than archers
. Slighly higher base damage than archers, with a bonus vs Cav/Large units
. Available in Fuedal age
. Serves as an earlier counter to armoured Cav such as Knights than what the Crossbowmen does, although it is inferior to Crossbowmen
. Costs the same as a spearmen does
. Countered by Cav, MaA, archers, etc.

The idea is an early missile unit specifically designed to counter early cav rushes when supported with say spearmen but which is vulnerable if left exposed to a direct cav charge or shot by archers.