But from my understanding, the first graphic is official. It shows KBTM's proposal for a BMO type vehicle. The previous BMO-1 was a BMP-2 with half of the back seats replaced with a massive rack of RPO-shmel's. The dismounted infantry would use the rockets to clear buildings. There was also a APC-esque version based on the T-72 called the BMO-T. The version shown by KBTM is called the BMO-2 has 24 ready-to-fire thermobaric rockets attached to the turret, which also features a 30mm autocannon and what looks like a coaxial 7.62 PKT. The chassis is KBTM's proposal for the front-engined Armata.
The BMO family are engineer vehicles, as is the TOS-1 vehicle, so it would be interesting if they adapted a new vehicle to perform both missions by combining troop capacity plus a large rocket launcher mounted on top.
From the photos above (the one with the three models of the bridge layer, the TOS-1 lookalike, and the flat deck vehicle with the odd shaped pods in the rear) it seems they might not be trying to combine the BMO and the TOS, or they are offering all sorts of alternatives and are letting the military decide.
The second graphic shows Boomerang, Kurganets, and UAZ's front-engined Armata proposal. Notice that all three vehicles share the same turret. Also the Boomerang example is shown with an active protection system, I'm assuming this is "Standard-APS". On the turret, both the gunner and the commander sights are identical for part commonality. The turret's large bustle is worth noting, as ammunition is removed from the hull.
The boomerang model seems to have low angle smoke grenades fitted which suggests it is designed to pop smoke well clear of the vehicle rapidly.
All three vehicles have crew in the hull so I would suspect the ammo for the main armament will be in the turret below the turret ring. I suspect the rear turret bustle likely contains reloads for the ATGMs in a rack designed to reload the external launchers automatically.
I suspect these are the APC models of the vehicle families respectively.
Both KBTM and UAZ's proposals look very tall and very ugly in my opinion. What is filling the space above the tracks?. I want to see these machines driving around. I hate the uncertainty of these models.
Internal volume for troops and their gear plus fairly thick armour and of course fuel and all the other rubbish a modern soldier has to cart around with them.
The frontal armour will offer added protection because of its steep slope.
the rear turret bustle area could also contain munitions for the APS system, which I agree should be Standard on the Kurganets and Boomerang and likely Afghanistan on the Armata.