Inspired by the release of the Oathmark Cavalry (sprue photographs here:
https://ultravanillasmurf.blogspot.com/2021/05/oathmark-human-cavalry.html) I assembled the first one.

The horse is in two parts, with the whole of the head on one side - the joint being hidden by the reins.
The rider's body is in five parts (plus shield).
There are parts to equip all fifteen figures identically with Hand Weapon, spear or bow.
The supplied shields are the large rectangular ones found on the Oathmark Infantry sprues. Not sure how practical they are, and a different design would have been nice where you are building different forces using the same bodies (especially as both sets generate plenty of spare shields if you build the archer option). I do have a lot of shields to choose from so it is not so much of a problem.
There is a distinct family resemblance between the infantry and cavalry.

So having built one of the Oathmark cavalry, I thought I should do something about the Fireforge Northmen Cavalry I bought back in November 2020.
Sprue photographs here:
https://ultravanillasmurf.blogspot.com/2021/05/fireforge-northmen-cavalry.htmlThe horse is in four parts (head, left body, right body, tail) and the rider in six parts plus shield.

The riders can be armed with sword or spear and have the same circular (Aspis?) shields as the Northmen Infantry.
Here are the two figures.

Here the Northmen faces off against the Oathmark Human Infantry,

One thing - I have ridden a horse twice so I am not an expert, but neither of the figures appears to be holding on to the reins. Are warhorses controlled by gripping the horse's body?