If you keep a sharp eye out on roving bandit bands. You might be able to liberate some manhunters.
Once they have upgraded enough they turn into mounted units. Plus as you said the Scots have a mounted raider.
They are a bit lighter than I like mounted troops, but balance well with the other ground troops.
Personally I've recruited 9 hero's, set them all up as cavalry with lance on heavy hunters. Like a personal escort within the warband.
Using them along with some Rus Mercs or Jom Brothers, in a combined arms attack.
Let the foot troops attack from the front while cavalry harasses from the sides or attacks from the rear.
Its been fairly effective for me so far. Although I haven't yet gone toe to toe with many large army's.
I won 3 of the 4 fights I have been in, always outnumbered. Called one a draw, was just taking too many casualties.
Ran into a scots army that was at least half mounted and got out maneuvered. So I pulled out and went home to lick my wounds.
Overall I've been very fond of this mod. <S>