[Rules] AT fire *during* assault

[larrymm]

For item number 3, I believe the answer is no. Per 12.3 all enemy units in the hex must defend as one combined strength. The ATR at this point would be considered the enemy unit as the panzer initiated the assault. So they would have to defend with there DF rather than attack with their AT. This would also be similar to how short range INF AT works as well. They cannot use their AT on defense only when attacking.

From a practical perspective, I would not want to use the AT as the DF is higher anyway.

Agreed, 12.3 is explicit about defense, so ATR uses its DF in this case.

As for attacking with the ATR's 1 AT factor, it makes sense only if 1) there is any chance of success and 2) if its 3 DF doesn't give a column increase for assault.