I think you need to brush up on history a little. The Germans were beaten because they were overwhelmed by superior numbers and also because Hitler foolishly ordered 'no retreat' when the smart thing to do would have been to pull back and wait for the Russian attacks to loose momentum before counter attacking.
Suggesting that the Germans lost because they used their tanks defensively is pretty misleading and far from the truth.
I was actually thinking "Kursk" 1943 when hitler was still hoping to look for a decise battle and which by this time Guderian, one of the more attacking generals, was already preaching the doctrine of using tanks in a defensive manner.(rapid response defense / fluid defence or something like that was his new tank doctrine)
When the Kursk battle was lost and perhaps for lack of choices, the defensive doctrine crept in.
AS you say it was more the result of Hitlers policies rather than the use of tanks in a defensive manner, however if i remember correctly, the main premise of Guderians definsive strategy was to not commit to many forces in the front line in fact the barest minimum, just enough to suck the enemy in and then "wham". I think Mainstein pulled off a couple of local area wins usinging this strategy but for the rest of the war local area superiority was increasingly hard to achieve with tanks being sacrificed piece meal in a defensive mode in a no retreat policy.
IMO digging tanks in reduces ones mobility( an essential ingrediant of Guderians concept and possibly a rather negative approch. ( this is from memory after reading many reputable books on the war in the "eastern front" decades ago
Anyway I think we are both arriving at the same ideas in the proper use of the tank.
And you know better then all the Generals in the PLA?
OF COURSE I DONT. but i have read a few articles by military observers or military commanders.
Foremost amongst these is a certain Chinese Col. of the Canadian army who with an associate has spent decades analysing the structure and tactics of the PLA. There wouldnt be many released documents by the PLA they havent fully scrutanised over the years. His views and articles form the basis of my opinion on the PLA. ( Im sure theres a few members on this forun know who im referring to maybe by chance you have as well.)
Do you know what context those films were taken in? What was the mission and what were the opfor and ROE? Were these action shots or publicity shots? Etc.
The fact is they were uncomplimentary photos if used as publicity to show the PLA at its best.
A friend of mine , a serving officer in an armoured bat. also shook his head in a bemused manner when associating the photo with the caption describing battle manouvres or something. The tanks were lined up like ducks in a shooting gallery in an amusement park.