From what you have written, and correct me if I am wrong:
"I've changed the air transport on both independently loaded machines to distance 3 for 8 moves which is pretty much standard for me now. I'm virtually positive that I did NOT name the unit sets the same... if I changed the name at all."
This tells me you created a unit db on the linux box in the game on the linux box. Databases are dependent on matching up via a key. The key for this database on your PC is:
xxxx3_Move_Air_Transport
where xxxx is a four digit number. This number is random when generated.
If you built the DB on the Linux box instead of copying over the appropriate files/folders, this would cause the crash as the keys would be different. Databases need to come from a single source.
On the PC box , in the <GameDataDir>/udb is where the database set for this "xxxx3_Move_Air_Transport" resides. There will be a key file and an assets directory. Those need to be copied, and moved to the same udb dir on the Linux box.
--Mark