Independant Tank Brigade - 1941
Brigade HQ: Command stand
RHQ: Command tank/ armoured car platoon
Three tank battalions of three companies each (usually 1 KV-1, 1 T34-A, 2 T26 or BT platoons) for a total strength of 12 tank platoons. See notes. The regiment is treated as a single unit.
Motorised Rifle Battalion:
HQ stand in car/truck, 1 rifle/flamethrower platoon in truck, 1 45mm ATG platoon with truck/tractor , 1 82mm mortar platoon in truck, 1 37mm AA gun platoon with truck/tractor, three rifle companies of three platoons in trucks.
Notes: Early 1941 tanks would be all T26 or BT. Some regiments used T28 or T35 heavy tanks - in this case three battalions of T28s and one battalion of BTs. After Sept '41 only two tank battalions in tank regiment (optionally three). Authorised tank strength was much higher, but using at least one appropriate tank per company as a minimum is probably OK. Maybe have attached armoured car (recon) and flame tank platoons. The strength of the rifle battalion is ludicrously high as Soviet platoons were quite small, I'd probably go for two platoons per company and not three unless the Russian player is desperate.
These brigades were often attached to infantry divisions on a semi permanent basis, and used this way until well into 1942. I thought tank brigades also had a tank desant SMG company (tank riders) added to BHQ in late '41, but I'm probably wrong here too.
Rifle Division - 1941
Div HQ with Command stand, 1 cavalry/SMG recon platoon.
AT Battalion: HQ platoon and three companies each of 1 45mm AT gun platoon with truck/tractor.
Artillery Regiment: HQ and two battalions each of 2x76mm field guns and 1x122mm howitzer platoons.
Mortar Battalion: HQ and 2 120mm mortar platoons in trucks.
Engineer Battalion: HQ and 3 engineer platoons in trucks.
AA Battalion: HQ and 1 37mm AA gun platoon, 1 truck mounted Quad Maxim platoon.
Three Rifle Regiments:
RHQ: Command stand in truck./car, 76mm Infantry gun platoon with truck/tractor, 45mm AT gun platoon with truck/tractor, 82mm mortar platoon in truck, (after Oct 1941) SMG infantry company with two or three SMG platoons. (depending on your rules, also an AT rifle company).
Three Rifle battalions: HQ platoon, three companies of three rifle platoons each, plus HMG platoon.
Notes: This is a reasonable basis for the Russian infantry. Again, I think the rifle companies are way too strong and should only have two platoons each. By the end of 1941 most divisions were very understrength, and are probably best represented by dividing everything by three, so that the 'division' is approx a reinforced rifle regiment in strength. In this case amalgamate the infantry 'battalions' into regiments - so each regiment would have an HQ, six to nine rifle platoons and an HMG platoon. Support weapons would become divisional level assets.
These units were frequently heavily reinforced with extra artillery and engineer assets, and I also get the impression (probably erroneous) that they often had a battalion or so of tanks (maybe four -six platoons of garbage like T26s or whatever). They don't appear very strong on the the recon front! I believe they were authorised a recon company - cavalry?
Tank Division 1941
Div HQ: HQ platoon
AT Battalion: HQ and 3 companies each of 1 45mm AT gun platoon with truck/tractor
Artillery Regiment: HQ and two battalions each one 1 122mm and 1 152mm howitzer platoons.
Engineer Battalion: HQ and six engineer platoons in trucks.
AA Battalion: HQ, 76mm AA gun and two 37mm AA guns.
Light Tank Regiment:
RHQ: HQ tank/armoured car, recon armoured car platoon (BA 10 or BA 32)
Three battalions each of three companies of two light tank platoons(T26 or BT) each - eighteen tank platoons in all.
Medium Tank Regiment:
RHQ: HQ tank/armoured car, recon armoured car platoon.
Three battalions each of one medium company (two T34 platoons) and two light companies (two T26 or BT platoons each) for a total of six T34 platoons and 12 T26/BT platoons.
Motor Rifle Brigade.
RHQ: HQ platoon in car/truck, recon SMG/motorcycle platoon, 45mm AT gun platoon with truck/tractor, 76mm Infantry Gun platoon with truck/tractor, 2 82mm mortar platoons in trucks, 2 AAMG platoons in trucks, engineer platoon in truck and five rifle companies of three platoons (15 in all) in trucks.
Notes: Again, I think there are far too many infantry platoons in the rifle companies, but in this case it is supposed to be a brigade, so maybe it is OK. The tank strength again is pretty well what youy want to make it, though the Tank Divs did not have any 'heavy' tanks such as KV or T28/T35. If you are doing a Tank Div after any period of combat at all, these strengths coud easily be halved (quartered?). This division organisation was abolished in 1941 and replaced in late 1942 by the Tank Corps - in the interim in early 1942 there were just lots of tank brigades.
Airborne Battalion 1941
I only put these in because I've got one - airborne troops in 1941 were mainly used as elite infantry, but there were a few battalion sized drops as well (give those Germans something to think about as all the FJ lie dead on Crete).
HQ platoon and three companies each of three SMG platoons (arguably only two per compnay, but these were elite troops).
These troops also had some neat gliderborne light tank battalions, but I haven't bought any T-27s yet...