No, it wasnt a "standard doctrine" to fire at something until it catches on fire.
No, its completely irrelevant, as its still a huge number of shells fired per one tank claimed. Where claims could still be divided by two, and it would be optimistic.
Or until the crew bailed out visibly... such is not possible under low visibility conditions however and fire smoke and the cessation of motion is a more reliable method of gauging a successful penetration in combat... also doesnt affect the probability of two or more tanks engaging a single tango... which wastes shells too....
Most tanks were knocked-out by 1-2 hits, and burned as well.
lotsa pics showing tanks with as many as 3 or 4 perforation marks on the frontal hull/turret... then again its not a reliable measure of gauging soo yeah...
i also found this tidbit
"two bazooka teams and a 57mm anti-tank gun took several minutes to even disable a single Panzer - I believe it was a Mark III or IV. Their combined fire damaged it and tore a tread off, but it was only a chap running up and chucking a grenade through the hatch that finished it off."
another tidbit
"A T-34 was carted into a repair base with 17 penetrating hits once, but who knows how many it sustained after the crew bailed (or died). The same report states that, on average, a T-34 takes 1.8-ish penetrating hits before being knocked out."
and lastly
"A veteran's memoirs describe a Tiger hunting maneuver, where everyone in a T-34 but the gunner would hit the deck, and hope that the shell didn't get them as it flew through. With sufficiently ductile armour, and assuming the shell doesn't hit a gas tank on its way in, the tank might take a few hits before the crew is forced to bail."
now that doesnt exactly prove much as its not a statistic..... but its worth a read
this sorta aids my point though... engagements have occured at the 1800-2000m range while most kills occured at 800-400m for both guns... this means that even at 2000m the germans have already began shooting the enemy... where accuracy is dead awful.... LOS is worse and targets cannot be as easily gauged for a successful penetration..... this means a huge waste of shellsRange_______75mm gun_____88mm gun
100-200_______10.0%_________4.0%
200-400_______26.1%________14.0%
400-600_______33.5%________18.0%
600-800_______14.5%________31.2%
800-1000_______7.0%________13.5%
1000-1200______4.5%_________8.5%
1200-1400______3.6%_________7.6%
1400-1600______0.4%_________2.0%
1600-1800______0.4%_________0.7%
1800-2000______0.0%_________0.5%
Soviet tanks and assault guns knocked-out during 1943-1944, from Red army handbook.
another thing to note is LOS and morale.... something factored ingame.... the issue is morale is not kept as a constant between ingame and statistical comparisons.... it could be that those shots were all made while the crews were under return fire.... and just like ingame it makes accuracy really really bad..... issue is we dont have a statistic of a calm unstressed unit firing at a tank in combat conditions... rather all we have is a lumped up statistic that could have been made by suppressed or panicked units...
LOS in contrast means that potential sight blockers such as fog or smoke could have been present in those conditions... this worsens both accuracy and the ability to gauge a knocked out target... this is sorta simulated in SD... however tanks do not fire into the smoke as in real life...
the closest thing to a statistic concerning unstressed and calm unit firing at a tank in combat conditions is the accuracy tests done with the said german guns.... well all guns had this test but the german statistic is the most common
the thing is even in the best of conditions tank accuracy is still horrible in SD... and those "bad factors" in real life such as morale and LOS blocking are already simulated in SD.... with only multiple penetrations per target to KO being undermodeled... as a result realistically speaking those guns underperform to their real life counterparts....