Add two new trash infantry units:
Light Infantry Line: Cheap and fast infantry. Resistent to arrows. Strong vs siege and soft counter archers. Weak vs everything Else.
Stats (Feudal / Castle / Imp):
HP: 40 / 45 / 50
Attack: 4 / 5 / 5 (+0 / +6 / +10 vs siege)
MA: 0 / 0
PA: 1 / 2 / 3
Armor Classes: Infantry; Eagle warrior armor
Speed: 1.1 / 1.2 / 1.2
Cost: 35F 35 W
TT: 15 sec
In simple words, a foot version of scout-line. I really think that almost all civs need this unit. Not all upgrades for every civ, of course. Developing a different unit-line just for riding or having some movility feels awkward, but having an alternative, more accesible although inferior could be a good addition that synnergizes specially well in some infantry civs.