I'm not sure this would work for historical campaigns due to important areas of operation taking place on the edges of the map.
(By the way, i seem to remember there was a Croatia map WIP at one time, anyone knows what happened to that?)
There was a lot of interesting aerial combat taking place in the south, along the borders with Albania and Greece against the Italians, as well against Germans advancing from Bulgaria. So this would have to be somewhat expanded towards south. As early as 1940 the Italians "mistakenly" bombed Bitola on the Greek-Yugoslav border, and the Yugoslavs reciprocated in 1941 by successfully bombing a number of Italian targets in Albania.
Also, the withdrawing Yugoslav Government flew from Niksic in Montenegro on to Athens in Greece, and later on to Crete. So we definitely need a bit more on the map in the south-east.
In the north-east the map area is good, there have been Yugoslav bombing runs onto Szeged and Baja in Hungary and the main German airbase for attacking Belgrade was Arad in Romania.
The north-west however would need to be expanded to allow attacks on Klagenfurt and Graz in Austria (and vice versa, from there to targets in Slovenia and Croatia).
Also, the hydroplanes stationed at Kotor, Montenegro would need to be able to operate over the Dalmatian coast and islands.
Ditto for Sarajevo which finds itself on the border between the two maps, but was the main airbase covering central Yugoslavia, the so-called "Fortress Bosnia". Maybe an overlap so it is included on both east and west maps.
For Mostar, which was also one of the most important airbases and where the pilot academy used to be, there should be possible to fly from there to Belgrade (the Me 109 unit that defended Belgrade was transferred from Mostar shortly before the German attack).
Generally, for a semi-historical campaign centered on defending Belgrade one could follow a path like this:
- Training in Mostar, 1939 (biplanes, graduating from a trainer to a Hawker Fury)
- 1940 Mostar, transitioning to Me 109; first border incidents with Italians over Dalmatia (historically, a single G.50 was intercepted and shot down)
- transfer to Belgrade airbase for a scheduled overhaul early 1941
- March 1941, put on high alert, moved to dispersal field near Belgrade
- April 6, dawn patrol, first contact with the enemy
- several sorties over the day intercepting mass formations of bombers.
- increasingly worsening odds over the next couple days as attrition reduces the number of the defenders while the Germans seemingly have an endless supply of reserves; multiple sorties flown by each Yugoslav pilot every day, some chalk up over a dozen takeoffs in a day. The weather worsens.
- April 9, flight before the advancing Germans in blinding rain and fog from Belgrade to Bijeljina.
- April 10, the Independent State of Croatia was proclaimed; historically, this is when the remaining planes were burned on the ground at Bijeljina to prevent capture, but we might fancy a single plane flying on fuel collected from other planes from Bijeljina to the Rajlovac airbase near Sarajevo, where the Yugoslav High Command was stationed.
- After arriving to Rajlovac, the pilot is being directed to escort a transport plane with high ranking officials fleeing Sarajevo for Niksic; the King and the Government, as well as the Yugolsav gold reserves are already there.
- As the Government evacuates to Greece from Niksic flying in SM.79's, there's one last plane left but no pilot; nobody is in charge, as the Yugoslav chain of command fell to pieces. Our pilot sets his trusty 109 on fire and decides to fly the remaining SM.79 out to Athens loaded with refugees...