Actually, you have written a big pile of nonsence.
Germany didn't want to invade Poland at all, but were forced too because of Józef Beck idiotic foreign policy. From 1938, especially after Poland participation in "Czechoslovakia case" and annexing Tesin Poland was thought to be Germany biggest ally (more than Italy!). From Hitler point of view and Foreign Affairs ministry Poland was ideal. It was incredibly anti-communist, they already had non-agression pact from 1934 and if it would be convinced, the entire Eastern Front would be safe unti they will deal with France and Britain. Hitler thought that Poland would make a great ally to fight Soviet Union - his ideological grand enemy.
However, in 1938 Germany asked Józef Beck if "the conflict with France would erupt" what would be his policy. And he answered that he would keep the promise and help France. Ministry of Foreign Affairs was really dissatisfied, but they tried again, again and again. However, in the late 1938 they realised Józef Beck was complete imbecile, and later Poland accepted "guarantee" from Great Britain, making them de facto part of anti-German coalition. Because Germany knew France wouldn't prepere massive offensive in the first months of war, they decided to crush Poland first to secure eastern flank and that's why they created Ribbentrop-Molotov pact out of really nowhere.
If you really want to recreate how it looked in history, you can create event chain like this:
1. Poland guarantees France from the beginning of the game.
2. Poland can choose either to claim Tesin in 1938 (Historical) or stand in Czechoslovakia defence.
3. If Historical path chosen, there should be event about "Conflict in West case". Historical option would make Poland continue to guarantee France. However not-historical outcome would make Poland abandon it.
4. If unhistorical path chosen - instead of "Danzig of War" event there should be event about "proposition of anti-soviet alliance". How Józef Zychowicz, famous polish historian called it - "Pact Ribbentop-Beck", making Poland lose Danzig to Germany, but making Poland part of Axis.
To make the game balanced, AI should never choose "unhistorical" way, because it would make player Germany job far too easy. But it would be really interesting way to play Poland. And before any critique will appear, Germany-Poland alliance was very probable, and many historics have written about it. Also, if you have access to Mackiewicz's diaries and the works of Polish emigration in Britain, you can see how many of them were mad becaue of Beck idiotic "honourable" policy and what it led too.