The counter for military units doesn’t quite make sense when interacting with relic conversions.
Attached is an image of a game result where I believe this happened last week.
The player thanks (me) has a Military Count of -4 around the 22minute mark.
This may be intended behavior, but it is confusing at the score screen and may not be what you want to communicate to players (it makes it look like the game is broken as there is no explanation).
My hypothesis for this is, for example, if I have trained 5 of my own units, convert 10 enemy units (with an actual total of 15), and then 9 of them die, my military count will be (5-9) = -4. The screenshot above is from a game where I had barely any units as HRE and then converted a raiding party with a prelate with relic, creating the necessary conditions for this outcome.
This must be happening because the game only increments when you create your own units, but decrements it in all cases when a unit is killed. As a result it seems like it does not handle the edge cases where the number of killed converted units exceeds the current amount of trained, live units.