Finally I managed to have the bug repeat itself, hopefully recoreded in the log. What essentially happens is this.
I Siege, I lose a unit *often Goblin Prowler due to fragility* so by the end if I was careless with them I tend to have around 56/60 or so *spike traps are eviiiiiil!* Due to the loot I can replace it, whatever, so I go to the world map and select army. The thing is, it says it is at 60/60. Confused I check with View Army and sure enough i have no units missing, the dead goblin prowlers are there and i can move them and everything. *note, not ALL of them died, just a few*. Thinking it is all fine I go for another siege. I enter battle with 56/60. Makes sense but even after this next one it still says 60/60. The only way I have found to cure this curse, is to basically execute all units of that type if one of them dies, a bit harsh even for Orc kind. This at one point got so bad *since you cant tell WHICH of the units are bugged* that i was doing sieges that on the map said i had 60/60 and high str, but when i entered a siege i had around 41/60 *before I started the executions* due to ghost units. Due to this I had a much weaker army than I should have. Granted, it took many sieges to cause that much damage without troop replacement, but it is quite annoying to have to replace anywhere from 1-16 if just one dies due to wanting to be at full strength.
Not a major thing, but downright annoying. Though, Vassal gold is very helpful for alienating the gold cost from the Executions to train the new recruits who likely will end up Executed as well.
"To underestimate a Goblin Horde is to stare into the face of Hell and think it to be heaven." ~ Svulnar, The Goblin King