I decided to modify the Poland scenario to allow free form deployment.
However it seems that you cannot force deployment mode without a prior map, so instead I added 1 more turn to Poland ( 17->18 ), removed all the non-aux units and added 4 "invisible" cities around which you can deploy:

However I ran into a problem trying to add prestige via triggers. From what I understand, the first time a trigger can grant prestige is after the 1st turn. That means you couldn't purchase the majority of your army before the the 2nd turn and move them before the 3rd turn.
Obviously the Poles do not sit idly by while you wait for your army to become active.
Deploy Point Nord will be raided by the Polish Cavalry and your Slovakian allies will get bombarded by the Polish Air Force.
Thus the only solution is that if you decide to use this map then you should manually add 2245* Prestige to the starting funds for the 1939 Campaign.
You can find the starting funds at Panzer Corps\Data\Campaign.pzdat
Change 964 to 3209, save and you're done.

Poland.pzscn @
[Download below]
P.S. Remember to back up the relevant files before overwriting/modifying.
- Wehr. Inf. 3x 127
Wehr. Inf. Mech. 2x 177
Gebirgs. 1x 127
Panzer 1A 1x 107
Panzer 1b 1x 108
Panzer 2C 1x 192
10.5cm leFH18 1x 242
BF109E 1x 410
BF110C 1x 324
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Total: 2245