Kull Cataphracts
Let's assume you have a combined force of mounted humans and Kull.
I believe the most effective use would be to mirror Parthian tactics and use the mounted humans as horse archers. Their job is to weave in and out of range, harass strong points and hammer weak points.
The Kull would replace the super heavily arnoured cavalry (Cataphracts) to exploit the chaos created by horse archers with crushing charges. Once a charge completely obliterates an enemy formation, the more numerous horse archers also charge to overwhelm and finish off.
The beauty of using horse archers is that they have always worked best in history, when command structures allowed them to move in relatively small units and attack from many different angles simultaneously. In an army led by at least one, preferably more dragons and riders, the commanders could use their birds eye view to give direct commands through their minds to separate units in real time. That would turn them into the Mongol horde on steroids.
What I'm stuck on is best weapons/equipment for Kull Caraphracts. Armoured horn to toe and covered by horse archers, do they need shields?
I don't like the idea of couched lances with our without shields on a super sized footsoldier. So what about Kull sized Axes (2 one-handed or 1 two-handed), hammers or swords? That might be best for charging infantry formations but what about enemy cavalry?
Best I can come up with is to equip them with Kull sized
A. Hutvirs (less crushing force but ability to stab as well as slice - and imagine them just spinning in a circle with the two blades sticking out...)
or
B. Maces (think mace offered to Eragon after losing Zarroc or Sauron's mace from fellowship movie).
but I'm interested in your opinions.
As a side note, I'd equip and use dwarfs like Roman legions (sub crossbows for javelins) and normal Urgals like Greek phalanxes. Humans provide cavalry and navy. Led by dragons and riders and saturated with elven mages, who will challenge the united forces of Alagaesia?