The 9P149 "Shturm-S" (modeled in game as the "MT-LB Shturm-S") was designed as a high capability counterpart to the BRDM-2 tank destroyers, in game it does not perform as such. The 9P149 could fire any missile from the 9M114/9M120 Kokon/Ataka family that is ITF in game, meaning it can and should be able to fire Kokon-M and Ataka.
"MT-LB Shturm-S" moves to CatB and recieves Kokon-M as missile armament.
Create "Shturm-S" CatA tank destroyer with 9M120 Ataka as missile armament.
Potential unit cards to follow
The 9P149 tank destroyer was designed to be a high capability tank destroyer to supplement the capabilities of the BRDM-2 based tank destoyers. Unfortunately it is stuck with a CatC missile dating back from 1976/1978 depending on where you are reading. At the very least the system needs to be bumped to CatB with the Kokon-M in order to make it a relevant system in the RD timeframe. Furthermore I suggest it is necessary to create a CatA Ataka armed ATGM carrier. The current "MT-LB Shturm-S" does not function well as a tank destroyer against anything other than light and medium tanks and its current missile is nothing more than a glorified longer range Konkurs at 20 ap.
This does however seem like a slightly problematic proposal at first because there are really no distinct 9P149 sub-variants ITF that we can use to create the CatA carrier but that assumes that the existing model in game is named properly... which it isn't! The system is designated "9P149 Shturm-S" or more often "Shturm-S", however it is named in game as "MT-LB Shturm-S" which gives us all the leeway we need to accurately name the successor CatA tank destroyer with a different yet accurate name, simply as "Shturm-S" While we could manufacture some semi-fictional name like "Shturm-M", call the original "Shturm" or pilfer the OOTF "Shturm-SM" the truth is "MT-LB" has really no place in the name and allows us to create a new variant with the system's proper name "Shturm-S", if anything should be added it should be "9P149 Shturm-S"
Finally where do we find the room without adding a unit? The 1960s BRDM-2 Malyutka-P is absurdly obsolete for the USSR deck and has no place in RD. If anything its place should be held by the 9P137 Fleyta but let's not kid ourselves, it just doesn't belong. It's not even in the class of the M150. The BRDM-2 Malyutka-P will be re-rolled into the CatA 9P149 "Shturm-S"
This is a case of copy paste. The CatB "MT-LB Shturm-S" simply needs its missile (Kokon-M) and service date changed while all the re-rolled unit needs is the proper name "Shturm-S"/"9P149 Shturm-S" the Ataka missile and a CatA service date. I'm sure the community would be happy to provide a skin if necessary and there is a beautiful OD skin with white exercise markings already out there.
USSR is still left with the CatC BRDM-2 Konkurs as an all decks CatC tank destroyer in addition to the massive proliferation of 9M14's already existing on CatC BMP-1/BMD-1 so there is no perceptible capability loss due to the absence of BRDM-2 Malyutka-P (which is under-modeled anyway...).
Furthermore this change does not provide to the USSR anything that does not exist in a Bluefor decks and coalitions like US/Vikings etc etc..
Most Bluefor decks contain both wheeled and tracked variants of their high tier ATGMs and this change would leave the USSR with BRDM-2 Konkurs-M and "Shturm-S"/"9P149 Shturm-S" (Ataka) as its top tier wheeled/tracked duality much like the TOW-2 LAV/M113 TUA duality and other similar arrangements on the other side of the curtain. In short it does not unduly overweight the capability balance between the USSR and adversaries, in fact most will still have access to more TOW-2 class high tier ATGMs on TD platforms than USSR.
For no increase in the unit count and no holes in CatC,
USSR loses CatC ATGM carrier with Kokon 2800m, 55% accuracy 20 AP missile.
USSR gains CatB ATGM carrier with Kokon-M 2800m, 55% accuracy 22 AP missile. (Less accuracy than ITOW but more AP)
USSR gains CatA ATGM carrier with Ataka 2800m, 65% accuracy 25 AP missile. (Less accuracy than TOW-2 but more range)
Even in CatA with Ataka USSR is forced to trade accuracy for range, furthermore lacks the stealth of recon TOW-2 launchers. While possessing longer range, each missile is noticeably inferior in accuracy to widely proliferated blue counterparts at their capability level, trading range for accuracy. Furthermore launching platform is, remember, far more vulnerable at 1/1/1/1 compared to 2/2/1/1 on most if not all mid to high tier Bluefor ATGM tank destroyers and it on average is 5+ km/h slower than those platforms, decidedly slower than the wheeled carriers.