At least if we want to bring an Infantry line to the state it can compete with the other “Power Units”.
I see mainly three options for that:
A) Make Scorpions “trash”, but less generally powerful
B) A new trash Infantry line (Axeman eg) that counters other Infantry
C) A new Archer Line speciaised to counter Infantry EG the Lightbowman
And some Infantry units could get a small resistance to that anti-Infantry bonus damage of the trash counter unit. Not necessarily the Militia Line (Gambesons could give a small amount), but more expensive stuff like TK and Huskarls.