Should Chybisa ever get a deal like the Hungarians had......
I've thought of modifying Chyssbia a bit with some "Hodiri Settlers".
Something along the lines where a few disaffected Hodiri, perhaps a tribe that has been absorbed by another and there are some refugees from this, or even just a tribe being pushed to almost extinction by competition for prime land strikes a deal with the Chysbian crown.
They get a handful of manors, and provide a horseman per 600-800 acres.
They would have more horses of course than the average manor, and probably more livestock than the average manor, but less cropland.
And I'd think the "manor lords" at least would wear mail armour - and over time, maybe a few generations become more as "knights" than light horse, though their accompanying horse would still be the light horse archer types.
Of course, the ridiculously high cost of the warhorse in Hmanor would have to be modified. The other thing - the Hodiri are really only constrained from wearing heavy armour by the carrying capacity designated in the rules, which is not accurate. Cavalry mounts could easily carry 25-30% of their body weight historically, this was considered a normal load. Ponies, such as what the Hodiri are to have could actually carry a higher % of weight with their shorter backs, similar to Arabic and other hotblood horses.