In 1941? Yeah in December at the far end of their inadequate logistics, after being burned up in repeatedly attacking without sufficient replacements (manpower and equipment was held back to form new divisions and rebuild units for a 1942 campaign), and had a major part of their air support withdrawn from all over the front. They were rolled back to a point, then held the line, gave better than they got, then counterattacked in 1942 and inflicted horribly disproportionate casualties after the campaign lasted far long than had been planned on. It's a nuanced issue beyond the line moving on a map and the T-34 was not the reason for Soviet success, which was the point of the statement you quoted.
Let's really run the tape shall we?
1941 - GOAL: Destroy the USSR, capture Moscow and Leningrad. Result: Failed (close but not close enough)
1942 - GOAL: Complete conquest of USSR by destroying Red Army; capture oil fields near Baku. Result: Utter failure, including the total destruction of a field army and the near destruction of Army Group B.
1943 - GOAL: Defeat Red Army's offensive potential to a degree that troops can be redeployed to face imminent WAllied offensives. Secondary goal to reassert dominance over battlefield and Eastern Front. (Operation Citadel) Result: Destruction of 9th Army and Army Group South as effective Combat formation. Effective end of Heer as an offensive force.
1944 - Goal: Hold territory gained, especially Ukraine/Crimea, Belorussia, Poland, defend Romanian oil facilities. Result: Loss of virtually all territory gained in USSR with remaining forces trapped in unsupportable pockets. Romania invaded, switches side to fight with Allies.
1945 - GOAL: Survival of 3rd Reich as political entity. Result: Red Army and WAllies meet at Oder River. Berlin captured by Red Army. Germany partitioned between four main Allied powers. Full reunification does not occur until 1991 when USSR dissolves due to internal pressures.
Find the actual
strategic success. Sure the Heer gained ground, captured (and later killed through neglect and plain old brutality) millions of Red Army troops and managed to visit Hell on Earth to most of the Western USSR, but they never achieved ONE of their major operational goals in the East. Can it be argued that the goals were vastly over optimistic? Absolutely. The fact remains that the goals were set by Berlin (both by Hitler
and the General Staff) and every single time the strategic goal was not achieved. EVERY SINGLE TIME.
It gets tiresome after a while to continue to point out, time and again, that the Reich hit its high water mark in late October of 1941 (Arguably as early as September by some measures). From that point forward for every "success" there was a near immediate blowback that resulted in Reich failure. The Allies didn't suddenly say a magic word in early spring 1945 or defeat the Reich because they came up with a single war winning miracle weapon. The drove the Wehrmacht back into itself in the same manner that a car crusher turns a 3 meter long car into a one square meter cube, in a constant, incredibly violent unrelenting application of pure overwhelming force.
The last real uncomplicated success for the Heer was when it reached the Channel coast in June of 1940.