Hi Mike!
You are absolutely right, I always post something confused, which I suck from my fingers. Sorry, thats kidding.
But seriously:
If your only source is a Men-at-Arms booklet, then YOU have researched too little!
There was a Russian army at that time, which consisted of
- Infantry (Pikemen and Streltsi)...:
- Artillery...:
- Cavalry (light and heavy/armored)...:
And there were the Oprichniki!
Ivan IV created the Oprichniki because he did not trust the army!
And these Oprichniki had exactly the tasks and the look that I have described here!
- Mostly dark / black clothes
- Dog's head at the saddle
- broom.
(Or did you think I sucked even the pictures out of my fingers?)
In Russian historiography about the time of Ivan IV, a distinction is made between "Army" and "Oprichniki"!
And if you had really dealt with original sources, you could read there that the Oprichniki were not good as soldiers, because they usually fled the first shot!
They were trained for other "tasks", that of a gang that should suppress any internal resistance! A pure killer gang!
I recommend you as a source the "campaign" of Ivan IV against the city of Velikije Novgorod 1670.
"Cavalry" is a terminus for mounted army members!
Or what do you think your template of an Oprichnik with the broom intends, if it is a soldier ...?
However, what I'm writing here is ONLY at the time when the "Oprichnina" (опричнина, a kind of state in the state which belonged to Ivan IV personally) existed, and it existed from 1565 to 1572.
The "rest" of Russia at that time was called "Zemstzhina", and was governed by a council of the boyars.
Look at this map: Green, yellow and violet: Oprichnina, light red: Zemstzhina...:
So not even the dates that you mentioned above are correct!
The years from 1833 - 1584 (you write) do NOT denote the time of the "Oprichnina" / "Zemstzhina" but only the total reign of Ivan IV., (until 1547 his mother Helena Glinskaya ruled in his name because he was still a minor).
In short: Army is army, cavalry is cavalry - and Oprichniki were Oprichniki! I think YOU are the one of us who did bad research! Unfortunately there helps even no polemic.
Cheers
P.S. Please excuse me for writing this quite "clear", but I do not like it at all when someone quibbles a post by myself as "wrong" and "confused", who apparently has been very superficially occupied with the subject itself.