AT fire in assault hexes

[leonard]

Still some doubts...especially regarding item nr 3 in Peter's summary.

We were recently playtesting one scenario of Fire & Sword: see picture (sorry for bad quality).
The T34/85 has to exit through the north edge for victory conditions. The Soviet chooses to a Move action.
   

Then the T34/85 moves directly to the Panther on the left et declares an Overrun (See Optional rules). We have resolved the overrun like a normal assault : simultaneity, Soviet attacks on column 9 - 1 (overrun) -2 (town) = column 1, Panther defends on column 9 - 1 (overrun) = column 5. Result = nothing and the T34/85 passes through...
However, when re-reading the rules for overrun, it seems clear that the attacker and the defender may opt for Anti-tank fire instead of assault which seem to justify the otherwise strange exception in 12.52. In this case, the tanks would exchange simultaneous shots : T34/85 fires with 7 -1 (overrun) -1 (town) = 5 so that it needs 11 or 12 to hit, Panther fires with 8 -1 (overrun = movement ?) -1 (town) = 6 so that it needs 9 or more to hit.
What do you think ?