The map shows the historical municipalities that in 1874 and 1926 unify to make the "Grande Genova". The base is from the site of Comune di Genova (<https://mappe.comune.genova.it/MapStore2/#/viewer>).
This is partially true. When I thought and tried the map I didn't consider a game against AI, but after your review I played and I won a lot of time. It's true that there is a problem in the match 2 vs 4, but it's a very little map: it's obvious that you can't do a game like that. Instead, it's good if you play with balanced teams (1 vs 1, 2 vs 2 etc.), especially with the initial distribution "Total war".