Not sure... I may have misinterpreted it:Does this actually work?
L4.4 Pushback Phase
In each Combat Round, there is a chance that a Pushback effect
may occur. This is more likely to happen when the Defender
has suffered serious Combat losses and has been forced to
Withdraw. If it is determined a Pushback has occurred, some
collateral damage is inflicted upon the Infrastructure and any
Installations that exist within that province.
L6.1 Retreat
Instead of simply having the losing side’s units Retreat into
the next province, HOI 3 tracks Retreat more carefully.
Individual Divisions will Retreat, and not the whole army.
Each unit Retreats a certain distance through the province,
per Round, at the rate at which the Attacker Advances. If the
Attacker Advances 50% of the way through the province,
the Defender Retreats through 50% of the province. In order
to fully push the Defender out of the province, the Attacker
must push it 100% of the way. In game terms, the percentage
of the battle won is considered equivalent to the amount
of the province’s territory left to capture.
A unit that loses all of its Organisation is forced to begin
Retreating. Some Units (such as those with a deficiency of
Officers (see L6.4) may be forced to Withdraw before their
Organisation reaches zero.
For obvious reasons, a Retreating unit may never be
ordered to Attack. Retreating Brigades also may not participate
in a second Defensive battle.