I just want to ask if there are opportunities to add long campaigns.
Your tools to modify your own ongoing generated campaing(s) are very powerful - (adding, redrawing maps, modyfing VH locations etc). A generated camapaign will give you resonable battle locations for pretty much all countries.
For a lot of major conflicts game already does it just not called a long campaign.
Example pick sides & timeframe that a war did happen & watch the map name as it generates. If the time is right you will see maps with specific place names or even operation so & so & the AI will buy a suitable force for it.