THANK YOU!
I enabled cheat mode and moved my army to the ass end of nowhere. Disbanded... It didnt look good because the game was still very laggy, but i left time running and a day past without crashing - but it was still laggy.
I saved and quit and reloaded... game is smooth again

Its entirely possible of course that something is still very broken, I will report back here if it is once I get to play the game again (not likely for a couple of weeks).
Oh, the mod I installed is "Slow armies fix", i got that one because of how it was implimented (they discard rather than sell, I assumed that would work better in my situation).
Edit: To clarify some things. It looks like its definitely a track that is causing the scouting spam to crash the game.
If I move my army with cheat mode right after loading, I can move around and the game is smooth (is stutter for a second and recovers), If I then move my army back to where it started (both with cheat mode or by running them there, as soon as they get without sight range the game crashes (and spams scout xp).
Taleworlds you might want to take a look.