How to check how many soldiers of a blueprint died

I have a little question: what I want to do is to check how many soldiers (individual soldiers, not whole squads) of a certain type and player died. Basically I want to reverse the function Stats_UnitSoldierKills which checks how many soldiers have been killed by an sbp, but I want to check how many soldiers of an ebp have been killed. Can anyone tell me how to write such a function or tell where to find Stats_UnitSoldierKills in the data.sga archive so can have a look at it?

Unfortunately, I believe this to be impossible. The Stats_* functions are C functions exposed to Lua, so there's no way to "find" the function to look at it - and even if you could, you can't modify the C code, anyways.

There are a few undocumented functions, but they do not provide anything more than what the others already do. But, they might be useful in other ways:

Stats_BeginBalanceStatsDump(string filename)
Creates a .csv file in /LogFiles that looks like: gamestats-<filename>-01260.2019-06-08.10-20-01.csv; it starts out blank.

Stats_BalancePrint(string row)
If a balance stats dump has begun, prints a row to the current file.

Stats_EndBalanceStatsDump()
Closes the current file for a balance stats dump.

Stats_DumpFramesToDisk(string ?)
I haven't been able to figure this one out, yet. All I know is that it only takes a string. Maybe filename?

Stats_GetScenarioName()
Returns the current scenario name.

Stats_ReportGameStats(string filename, float realTime)
Creates a .lua file in /LogFiles that looks like: <filename>.lua; it prints all of the current stats for the game, and will set realTime to "minutes : seconds" of the passed in float (which I believe are seconds). I'm not 100% sure what that's for.

The closest you could get to what you're looking for is to handle the GE_EntityKilled event and maybe do a Stats_BalancePrint or something to log the entity's blueprint at time of death. However, I don't think there's a way to figure out who killed that entity.

Alright thanks for the help!

If you really needed too, you could check for slot items. Give each member of the squad a dummy slot item, and check how many of said items the squad has in its possession. You might need a proper mod for that.