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I donβt play top tier, but generally you want your lineup to compliment each other and usually try to be at the same BR or fairly close. Maybe playing as Russia, it might not be an issue (Thanks to Gaijin wunderweapons).
Drop 11.0 vehicle, and try to get a better CAS (if you tend to fly) until you have the ability to create another lineup that matches in BR.
Regarding buying, Iβll leave that to others who play those higher tiers.
First off:
This is extremely good advice. Although it can be a bit difficult for some nations at certain BRs. In this case the 11.0 T-90A will make it so that you will see the top BR premiums at 12.0 basically every game, you will likely get a far better match maker with more down tiers by removing it.
11.7 is a good line up (or was before the BMPT premium spam, I have zero idea how bad the ODL is currently), you have the T-80U/UK, T-72B3, BMP-2M is still somewhat viable as a light tank, 2S6 is still usable for SPAA (Iβm not sure how good the Tor is), the Mig-27 and now the BMPT in the TT as well.
If you just go for the B3A you will be facing top tier CAS and tanks with no SPAA (I just remembered you get free SPAA now, but still) or viable back up vehicles.
Also IMO the T-80s are all better tanks than the T-72/90s.
