Thanks , that shouldnt be the case no, they should have a lot of space
Each Hitching post are separated by 2 empty tiles and they have lot of room to roam freely.
Now there is only 1 tile empty between hitching post and pali and it could be related to the bug you mention BUT I find highly suspicious they'd all disapear in 6-7h while I was sleeping and not even one before that.
While my death is semi recent (2 days ago) it seems likely it's the root of the issue.
And there is just no way it's griefing , there is probably a very small window to shoot them to death if very patient for them to come to the right spot , but the corpse would be there.
Stealing there is just no way ( and they would have stole more valuable stuff anyway

)
Definitely bug, imo related to the death.