The Su-25SM3 currently has a BR of 12.7 in ground RB, and it is ridiculous. It only has x2 R-73 and x4 Kh-38MT. Compeered to the Su-30 with the armament it has at BR 13.0 or even its French counterpart Mirage-2000D at BR 12.7 with x2 Magic 2s and x7 AASM-250 Hammers. And this is not even considering its a Su-25 platform, very slow and un-maneuverable air frame. Combine this with the new SPAA that has been added, the Su-25SM3 just doesn’t have a point anymore.
Giving it a BR of 12.0 wont do much for when you get an uptier to BR 13.0, but at least it will be good in a downtier at BR 11.0. Tell me this, when was the last time you saw anyone using an Su-25SMT in game?
Not only this, but it will actual give USSR / Russia a good CAS option for BR 12.0 Something they are currently lacking. Leaving you with the only option but to take the Su-24M Su-25T out. Both of these planes lack thermal sights.