I just revised my frontline editor, and created this one for SPAW2019FC multiplayer:


The black dots are bases, the blue ones are targets, and the red ones are the frontline nodes.
It would be crazy for a historical theatre, but if you check it out there are several areas with bases either side of the frontline, but close together.
These areas are ideal for ground-started multiplayer missions because multiplayer missions are flown in real time, and there is no time acceleration.
If the mission is ground-started then the AI friendly secondary planes, and the AI enemy planes all begin to take off from their respective bases as soon as the host starts his engine.

Playing multiplayer is sheer fun, and it is even better when the opposing bases are well positioned
You do not need to be an expert, and you can fly "host only" to try it out