Touché
If you want to talk SU76mm thats fine - I would assume the 76 to be firing APCR rounds if it saw a tiger and not be firing HE artillery rounds into the front of a tiger.
However back on topic - Flame weapons need to do more damage to counter fixed positions and discourage blobbing and encourage use of combined arms.
We should not encourage players to run into flames to get a snare they should be hard countered and squad wiped
Flame weapons do fixed damage per tick, but the rate of fire (tick) varies greatly from unit to unit. For example, the crocodile has a very high tick rate and will devastate infantry, even on retreat. The hetzer however, appears to have a stupidly low tick rate and is largely useless against anything other than a garrisoned squad with no AT capability.
Bottom line: A flat increase in flame damage for all units is not the issue and definitely a huge balance no-no.