Max,
It seems to me that asking someone to tell an SA-10 from an SA-20 from those views is a bit much.
As an aside, I find AFV recognition fun (in an army way). I have found that, at first, it is best to focus on the big things. Get to be able to tell the type of vehicle first.
I look at size, suspension, turret, shape (both of the hull and the turret) and the gun. Using these things one can quickly learn to tell a tracked APC from an IFV from a tank from an SP gun from a wheeled recce vehicle from a wheeled APC (although there will always be weird harolds).
Size can be a problem without a frame of reference, but it can be used to quickly differeniate between vehicles. The suspension may not always be visible, but tracks vs wheels is probably the easiest way to narrow down your choices. The presence or absence of a turret is another quick and easy way to narrow down choices. The size and shape of the turret can also be considered (some look like frying pans etc). The gun is usually quite obvious. A tank will tend to have a big gun that protrudes well beyond the front of the vehicle (assuming that the turret is over the front aspect). IFVs and recce vehicles will tend to have thin guns (25mm chain guns etc). SP arty vehicles will have large guns on a turret, but on an SP gun the turret will usually be set-back on the hull compared to a tank.
Once you've got the hang of quickly telling a tank from a wheeled APC or a tracked IFV or an SP gun you can then get fancy and start telling individual vehicles by name. I use the same things but go into details.
For the suspension you can look for things like the number of wheels and their layout for wheeled vehicles (4x4, 6x6, 8x8 - are they evenly spaced or are they grouped etc). For tracked vehicles you can count road wheels and also see if there is live or slack track. Slack track just hangs there above the road wheels while live track is supported by return rollers.
Looking at the turret you can focus on the shape (angular vs frying pan etc) and where it is set on the hull. Sight and episcope arrangements can also give clues. Bear in mind that stowage and camoflague can obscure things.
The gun can give details such as the precensce or absence of a fume extractor as well as the position of said fume extractor. A muzzle brake might be present. There might be a thermal sleeve. The mantlet might be distinctive. A muzzle reference system on the muzzle of the gun can also give a hint.
One big caveat is that with all the upgrades out there many of the details can change. Basic size, shape, turret and suspension, however, usually stay fairly consistent.
I am not suggesting that a pilot count roadwheels on a tank as he zooms in. You can use these little things in training, however, to give yourself some tricks. Over time, your brain will learn the "gestalt" of the AFV world and you will instantly recognize a T-80 where before you were counting the road wheels and their grouping along with counting the episcopes. That being said, telling a T-72 from a T-80 in combat conditions (ie not looking at a parade or arms show demo) might be stretching our capabilities and we should remain realistic.
It is the same thing when you are fishing. At first you are checking the eye location relative to the mouth and counting fins etc. Later, you can instantly tell a Smallmouth Bass from a Largemouth Bass because you have trained your mind to recognize it without having to think about it.
Cheers
