I suspect he means the thousands of light tanks... the T-26s and the BT light tanks of which there were probably 10-20 thousand at the start of the war.
They had three critical problems at the start of the war... the first was a lack of armour piercing ammo... even for the T-34s which hampered their use, but the most critical problem was the arrangement of crew in their tanks... the commander was also the gunner and the loader in the T-26 light tank which rendered it blind most of the time. The third problem was lack of communication and structure within their forces... a couple of tanks at a time would attack a german armoured force and get wiped out.
New lets be clear the main success of the German army was not their super tanks or amazing equipment... in most regards their tanks were inferior to Soviet tanks, but they were designed to be used more efficiently... the British and French tanks were no better in most respects... even the few rather well armed and armoured French tanks had poor crew layouts even though most had radios and proper tank structures to control them...
In recent years, revisionist works have challenged the standard narrative.
Since day one the western agenda has been to minimise the effect the eastern front had on the German war machine and try to push the idea that strategic bombing, lend lease, cold winters, and of course D Day won WWII in Europe.
BTW I enjoyed looking at the pictures on this thread again... if you like those old planes I can recommend the computer game Il-2:46 which is pretty much the old Il-2 Shturmovich game with all the Il-2 games compiled into one... the graphics of the ground are not amazing by todays standard, but the aircraft models are excellent and include detailed cockpits. With patches you can pretty much fly any plane or occupy any position within the aircraft including pilot, navigator, gunner, bomb aimer etc etc and there are hundreds of different planes and dozens of variations of many of those to fly. You can set yourself as invulnerable and with unlimited ammo and just fly around and have fun... the controls can be adapted to any hardware you have so if you have an aircraft control stick and a throttle system that allows for 4 or 6 engines then you can manually throttle appropriate aircraft including bombers from all air forces of the period.
wiki info that includes a link for the home website for the software.
Actually I see on the game website that it has been totally expanded so you can now play ground vehicles as well as aircraft...