2S38 indeed has poor armor and mobility but just like the Type 90 and Type 10 (Prototype) you have to rely on firepower, when compared to some Soviet vehicles, Chinese may have superior protection but the layout is sometimes questionable note the unusual large lower glacis.
The way Type 90 performs in match is based on the operator’s ability to understand the map and how clueless is the enemy team, I’ve never had issues using the Type 90 as I don’t rely on armor, it’s pretty mobile you should keep on the more every time.
T-80’s have better mobility than the Type 90’s too making flanking alot easier
also 2S38 if I recall is a SPAA designation but moved to light tank for balancing purposes. But it has a great weapon’s kit + proxy rounds for anti airs
Regarding T-80 mobility I can’t opine, I personally don’t like this tank, even, I prefer a T-72; 2S38 is a self-propelled anti-air gun in reality, and yes, is designated as light tank for balancing purposes and anti-air vehicles has the cheapest spawn point cost.
T80UD honestly should go up to 10.7. It’s where it belongs, and take the 2S38 with it. Both of them make 9.3 almost impossible to play, it’s lovely to constantly get uptiered into that combo being spammed.