Researching Red Army/Navy Units

[CtahhR]

Thank you for filling that blank. Some of the records from the first weeks are rather blurry.

Would anyone know the units of the

3rd Army's 11th Mechanised Corps (Disbanded 19/9/1941)

I know it consisted of;
29th Tank Division (Disbanded 14/7/1941), Subunits unknown.
33rd Tank Division (Disbanded 14/7/1941), Subunits unknown.
204th Motorised Division (Disbanded 19/9/1941), Subunits unknown.

It seems that the infantry, cavalry and air regiments are easier to pinpoint than the Tanks. The 3rd Army shrank (units on paper - without mention of manpower) from 12 Divisions and 4 Regiments down to only 6 Divisions and 3 Regiments in less than 4 months. Before Zhukov did some shuffling of the Front.

Also the subunits of the 3rd Army's 17th Mechanised Corps;

27th Tank Division (Disbanded 1/8/1941)
36th Tank Division (Disbanded 1/8/1941)
209th Motorised Division

I have also come across a strange position that seems nonsensical.

Platoon Commander, 4th Separate Brigade, 336th Rifle Regiment, Trans-Caucasus Front (early 1943).

I can't find a 4th Separate Brigade other than the 4th Separate Brigade Of Naval Infantry but that was Baltic Fleet. The 336th Rifle Regiment was part of the 5th Rifle Division pushing to Kursk from Moscow as part of the Brjansk Front at the time so that also doesn't fit. An almighty administrative error or am I missing something?