I have a bug when re-loading a game, where for example, I have a squad of 8 guardsmen units at 380/390 hp (took 10 damage in a fight). If I save, then reload that same turn, then the unit becomes a party of 4 guardsmen with appropriately reduced att/def stats as if it was created as a 4-party and the game forgets that is was a squad of 8.

I've also had parties of 4 reduce to lone individual units after reloading.

Had it happen to several units now. I only noticed the size of the unit decreasing in injured units only, if they're full-health they seem to re-load fine. The units have been left in a city as of save/reload, although it may have happened when wandering the wilderness too. The units were also grouped with other units when the reduction took place.