Big post with long lists incoming. And some questions as well, but at least I've solved the vehicle source question.
Yes, I'm definitely using brigades as the major combat element, not breaking it down into battalion groups. The BTG concept didn't work for the Russians, while the American brigade combat team is what I'm trying to reflect but with light infantry forces instead of mechanized troops.
National training center...not sure Serednya Slaviya's big enough for a dedicated area to romp around in the size of the NTC; it's only about 125 miles by 125 miles for the whole country. Our good neighbors in Poland should have plenty of training fields. I imagine the brigades rotate to eastern Poland for large-scale training; they'd deploy as brigades just as they would in fighting. Spend a few weeks a year in Poland for each brigade, and get good training against fellow NATO units.

Click to enlarge.
Since I'm copying American organization when it comes to a brigade combat team, I might as well look at the organization I'm working off of. I got rid of the mechanized infantry/tank combined-arms battalions, and only operating two Light Infantry battalions in each brigade instead of three.
This chart gives me a few questions - what makes up the Forward Support Companies in each of the battalions? I also notice that the Cavalry Squadron lost its artillery, but I made sure to make up with it with NEMO 120mm mortars.
As far as the makeup of the cavalry platoon, that changes some as well. I was originally going with four Patria AMVs and their infantry, two Panhard VBLs for scouts, two Centauros, and an AMV MEMO mortar system. Unfortunately that led to a platoon size of 78 personnel which was way too large. I traded two AMVs for two LMVs, and cut my platoon size down to 54 plus an attached Forward Observer and an attached Medic. Still big, but nearly half of it is vehicle crews.
AMV 1
Vehicle Crew
Driver (FB Mini Beryl)
Platoon Commander (FB Beryl)
Rifle Squad
Forward Observer (FB Beryl) (attached)
Squad Leader (FB Beryl)
Scout Team
Cavalry Scout (FB Beryl)
Cavalry Scout (FB Beryl)
Fire Team
Team Leader (FB Beryl + Pallad)
Grenadier (RPG-7, FB Beryl)
LMG Gunner (Ultimax 100, CZ-75)
Marksman (FR F2)
Fire Team
Team Leader (FB Beryl + Pallad)
Grenadier (RPG-7, FB Beryl)
LMG Gunner (Ultimax 100, CZ-75)
Rifleman (FB Beryl)
AMV 2
Vehicle Crew
Driver (FB Mini Beryl)
Platoon Sergeant (FB Beryl)
Rifle Squad
Medic (CZ-75) (attached)
Squad Leader (FB Beryl)
Scout Team
Cavalry Scout (FB Beryl)
Cavalry Scout (FB Beryl)
Fire Team
Team Leader (FB Beryl + Pallad)
Grenadier (RPG-7, FB Beryl)
LMG Gunner (Ultimax 100, CZ-75)
Rifleman (FB Beryl)
Fire Team
Team Leader (FB Beryl + Pallad)
Grenadier (RPG-7, FB Beryl)
LMG Gunner (Ultimax 100, CZ-75)
Rifleman (FB Beryl)
LMV 1
Driver (FB Mini Beryl)
Gunner (FB Mini Beryl)
Drone Operator (FB Beryl)
Scout Team
Cavalry Scout (FB Beryl)
Cavalry Scout (FB Beryl)
LMV 2
Driver (FB Mini Beryl)
Gunner (FB Mini Beryl)
Scout Team
Cavalry Scout (FB Beryl)
Cavalry Scout (FB Beryl)
LMV 3
Driver (FB Mini Beryl)
Gunner (FB Mini Beryl)
Scout Team
Cavalry Scout (FB Beryl)
Cavalry Scout (FB Beryl)
LMV 4
Driver (FB Mini Beryl)
Gunner (FB Mini Beryl)
Scout Team
Cavalry Scout (FB Beryl)
Cavalry Scout (FB Beryl)
Centauro 1
Commander (FB Mini Beryl)
Driver (FB Mini Beryl)
Gunner (FB Mini Beryl)
Loader (FB Mini Beryl)
Centauro 2
Commander (FB Mini Beryl)
Driver (FB Mini Beryl)
Gunner (FB Mini Beryl)
Loader (FB Mini Beryl)
AMV NEMO Mortar 1
Commander (FB Mini Beryl)
Driver (FB Mini Beryl)
Gunner (FB Mini Beryl)
Loader (FB Mini Beryl)
Nine vehicles in that platoon, though, so it's still going to be bulky.
It's not as heavily armed as it might seem, either; the AMVs only carry M2HB in a remote weapons station. Two of the LMVs also mount M2HB machine guns; the other two LMVs carry 40mm grenade launchers onboard. I figure the LMV's guns can be easily dismounted to set up in observation posts or other dug in positions. I was originally going to go with Panhard VBLs instead of LMVs, but the VBL meant not having a dedicated gunner or extra seat available.
For jobs requiring a translator or other personnel, the LMV seats five, so I have room for three mission specialists to attach to the platoon if necessary.
The revised cavalry squadron looks like this:
Squadron Command Troop
Command Team
Patria AMV x2
Mortar Platoon
Patria AMV NEMO (120mm Mortar) x4
Air Defense Platoon
SA-9 Gaskin x4
Patria AMV x2
SAM teams x4
Chemical Platoon
GAZ 66 4x4 Truck
Drone Platoon
GAZ 66 4x4 Truck x2
Medical Platoon
Patria AMV Ambulance x6
Supply Platoon
Ural 375D 6x6 Truck x10
Maintenance Platoon
MAN KAT 1 x3
Patria AMV x4
Motor Pool
UAZ 469 x20
GAZ 66 4x4 Truck x12
Cavalry Troop x3
B1 Centauro
Patria AMV (HQ Vehicle)
Patria AMV NEMO (120mm mortar) x2
Iveco LMV x3
Platoon x3
Patria AMV x2
Rifle Team x2
Scout Team
Iveco LMV x4
Scout Team
B1 Centauro x2
Patria AMV NEMO (120mm mortar)
Recon Troop
EBRC Jaguar x2
Recon Platoon
EBRC Jaguar x4
Recon Platoon
EBRC Jaguar x4
Gun Platoon
B1 Centauro x4
That comes to 35 Patria AMVs, 19 Patria AMV NEMOs, 45 Iveco LMVs, 25 B1 Centauros, 10 EBRC Jaguars, 4 SA-9 Gaskins, 15 GAZ-66s, 10 Ural 375Ds, and 3 MAN KAT 1s in each squadron. That's a lot of 120mm mortar fire from the various echelons of the squadron.
I wanted to find a place to slot at least a few EBRC Jaguars, and it made sense to put a mounted recon troop of dedicated reconaissance vehicles alongside the dismounted cavalry scouts. It partially replaces what would be the heavier tank troop in the cavalry squadron.
The Squadron Command platoons I have listed, would they apply to the Light Infantry battalion level command as well? That'd let me add up my total number of vehicles, and get an idea of how much I'm actually spending on hardware.
Light Brigade
Headquarters & Headquarters Company
Light Cavalry Squadron (AMV/Centauro)
Light Infantry Battalion
Light Infantry Battalion
Artillery Battalion (CAESAR/BM-21 Grad)
Brigade Engineer Battalion
Brigade Support Battalion
Light Brigade
Headquarters & Headquarters Company
Light Cavalry Squadron (AMV/Centauro)
Light Infantry Battalion
Light Infantry Battalion
Artillery Battalion (CAESAR/BM-21 Grad)
Brigade Engineer Battalion
Brigade Support Battalion
Support Brigade
Military Police Battalion
Intelligence Battalion
Military Intelligence Company
Counter-Intelligence Company
Signals-Intelligence Company
PSYOPs Company
Civil Affairs Company
Mortuary Affairs Company
As far as the artillery battalions go, I'm thinking each brigade has three batteries, one of CAESAR 155mm guns and two of BM-21 Grad rockets. That's a total of 12 tubes and 24 rocket launchers, which isn't terribly accurate but pretty heavy on the boom. I intend to replace those artillery pieces with CAESAR 155mm entirely, though I'm only doing that at one battery per year.
I cut it down to two fighting brigades instead of three; I had too many battalions that I didn't have enough troops to fill. As it is now, it comes to a total of 16 battalion-equivalents, with roughly 11,500 troops. That average comes to around 720 personnel per battalion. Considering my light infantry companies are 200-strong units, that about fits the numbers I'm seeing. That also cut my requirements for the number of vehicles in the force, losing the third cavalry squadron meant I could afford to modernize the cavalry forces, with the artillery next on the list.
tl;dr: I'm down to two brigades instead of three, I made the cavalry troops smaller, I modernized out most of the old Soviet hardware, I'm trying to copy the Infantry BCT, I don't have all the firepower in the cavalry that I used to.