Yeah, if there are more than 9 defenders, it would be a nice change to have to fight 9 defenders at a time, with the first 9 garrisoned units last.  But what you experienced in the beta might have been a bug (so many defenders).

I would like it if there are more defenders than 9, that the city defenders fight one battle first, AND the attacking army loses its remaining movement each time it attacks a city (but if you take a city you still automatically garrison your army).  However if town garrison + generated defenders is greater than 9, then the generated forces get fought in the first battle, and if the attacking player wins, they have to wait until next turn to defeat the garrisoned troops (including heroes) and take the city.

I would also like the bug where attacking a city with a full 9-unit army where the leader doesn't appear and counts as killed is fixed, if it isn't already.

Also, Morian attacked my newly created city with 8 additional units, and there was no room for Morian in the battle, so once I'd killed all the others I got the rewards for killing Morian as well.  I'm not sure if Morian can fit on a regular battle map if there are 8 others in the army.  If not, that needs to be fixed.  If the only maps Morian doesn't fit in are town maps, Morian either needs to not attract other units, or the map when attacking a city needs to be a lot bigger when Morian is in it.

Note: I think Morian is the only Wildland Boss that can remain after the Wildland is cleared, as the Swamp wildland only requires clearing all the "scarred" tiles.  So it's the only Wildland where you can plonk down a city before the boss is defeated.