I enabled a three mods and played. The mods: 0 A.D., Millennium A.D. and the formation fighting mod. I saved the game. Then I restarted the game and tried to load my saved game. The filter did not show me my saved game. I had the option to disable the filter. Selected my game and got a warning, saying that my mod selection is incompatible. The only difference the first and second time was the order in which I selected and activated the mods. The first time: 0 A.D., Millennium A.D. and the formation fighting mod. The second time: 0 A.D., the formation fighting mod and Millennium A.D. As you can see only the position of Millennium A.D. and the formation fighting mod are different. However, the order of the mod selection should not matter.