I believe that there are some slight issues with Russia within WarThunder.
The combination of the best SPAA and Kh-38MT platforms is one of them.
Their tanks are… actually quite okay. Somewhat good frontal protection with small weak-spots. The slow reverse speed teaches you not to rush ahead and forces a more methodical playstyle which is why US /Germany teams are bad. The realisation that even if you dont get Mobility killed, you cant pull out is a huge gamechanger. The ERA can eat a few shells - however yes it only is a problem at longer ranges where it reallt is pixel hunting, combined with the small silhouette of most Russian tanks.
Ive seen Russian tanks survive shots that no other western tank would have survived within War Thunder. Side shots that get absorbed by the cumulative effect of ERA, Armour, and Spall Liners. I have seen darts tumbling away from autoloader due to it - I havent noticed tumbling for darts for Western tanks yet. It is a realistic thing though. Hence “overperforming”.
The gun mantlet area, and the drivers hatch are weak spots for all modern tanks.
But lets compare it to the main rivals of Russian tanks: both Abrams and Leo 2 have a very weak and perhaps wrongly modelled Turret ring which is made worse by the claustrophobic ranges normally in game with the laser accurate guns. Its worse for the Abrams, shots from the UFP can be bounced into the turret ring that will pen it. Both tanks have abysmal and very big LFP, that is basically auto-pen, occassional bounce happens.
The gun depression… let me add that this game does a horrible at showcasing hull-down fighting. If anything its more akin to firing from a trench. With the exaggerated hills we have on the maps, even western tanks have to roll over it, exposing the LFP.
Lets say that Russian tank gun depression is good enough for typical hull-down fighting. Obviously not fighting over hills. But this is one thing that is both misunderstood by the player country and misrepresented by Gaijin.
As for maps. Some sections of the Top-tier maps would actually make very interesting Ground maps - I point here at the Denmark.
As for reload speed - this one is one of the dumbest ways to compare tanks in game as it really does not matter as much as people like to claim. Not saying it doesnt have a place. But lets put it down in a way: if you both shoot at each other at the same time, and dont kill each other, one of you might end up being firepower killed, meaning reload speed is less relevant. But lets say its not as important as people like to claim. The autoloader has both ups and downs: one less crew, fixed reload speed. Currently autoloader damage is very bad. You can totally manually load the gun in case of autoloader malfunction. Takes a lot of time and effort, but you can. But you can totally bin the good reload speed of an abrams if the loader is killed.
Also: you do get a HE shell. You can just aim at certain spots and overpressure superior western armour.
The other non-Russian tanks are all the definition of glass-cannon, with the Merkava being an outlier of falling behind in every category when it comes to Top-tier. The engine can absorb some spalling, but at times creates further spalling. Good depression, but see my comment on it further above. The crew survivability, which the Merkava is well-known for is okay. However its slow, big, and fairly average in armament, something shared by the Challenger tanks in game. Oh the Challenger has the worst weak-spots.
Russia is not underperforming objectively. Its people misunderstanding why people say Russian bias and what it actually means.
Lower BRs Russian tanks tend to be volumetric hell.
Then unique gimmicks. (Applique armour, Drozd on 55-AMD.
Then getting mechanics and weapons that outmatch everything. (Pantsir, Kh-38MT), with certain things performing bettet than Western counterparts.
27ER/ET against Sparrows.
The 73 is arguably better than the 9M.
Now the Kh-38MT.
Yeah I get that the R-77 performs worse than AMRAAMs but the AMRAAM meta is not that hard to counter.