During the past times when they were in 9.0 and 8.3,the T-64A and T-62 were already out of date for the lack of auxiliary equipments.The T-62 has poor mobility and poor shells,it also did not have diastimeter.T-64A has the same problems such as lack of laser diastimeter and long rod APFSDS.It is puzzling that why their rates are increased.
I personally have not had any issues using both of those tanks (T-62 and T-64A) in their battle ratings. The T-62 doesnβt really need a Laser rangefinder, in my opinion, due to the high scope zoom and its high velocity. On the other hand, the T-64A has an optic rangefinder, which is good enough in most situations. Moreover, the T-64A boasts great mobility and armor strong enough to withstand a few hits. When you combine all of these features with its low profile, it makes for a great tank.
I agree with your opinion. The T-64A(1971) is probably the worst 9.3 vehicle now, with no auxiliary equipments (for example, laser rangefinder, smoke grenade and AA MG) except for 2-plane stabilizer. It is worse than T-72A in all aspects, and can hardly survive any hits or defeat any opponents from 9.3 and higher BRs. It would be better if a later improved model of T-64A is introduced, or the T-64A(1971) is lowered to 9.0.
For T-62, the situation is similiar. The T-62 has only stabilizer, while vehicles like ZTZ-59D1 and Type 69-II already has laser rangefinder and smoke grenades. However, lowering it to 8.3 br will be a great threat for early MBT/medium tanks which cannot survive any shot from T-62βs cannon. It would be interesting if it simply receive Kontakt-1 or BDD armour upgrades, improving its protection.