Unit overlapping has caused issues in my gameplay. So many times I have been attacking only to find out there are more, sometimes twice the number of foes that I originally saw. Also, this could not be used to your advantage, because it happened randomly, and you could not do it yourself deliberately.
Sieges - I think the buildings will be more more durable than in other games, meaning it will take longer for trebs and catabults to knowck out defs - giving the defender more time to create a response. Also, stone res is beig used as ammo, and siege weapons will be much rarer - as was stated in the recent human buildings Fanfry. This will mean that there will prob never [unless you are fightin a hugely powerful player] be 20 trebs knocking on your door [or down your walls].
"Yes... I am writing a book. So far I have the page numbers." - unknown author.