That was changed years ago. The owner of the region is always the defender, except when you interrupt a takeover (where the TO forces are the defenders).
You've said this a few times...
That's...really not true. Deciding who the defender is is still quite complicated, and if Realm A is sitting in Realm B's region, and Realm B walks in, Realm A will be the defenders.
If this were not the case, region owners would always get their walls.
And you've replied this a few times...
Now, how many years ago are you thinking about, Tom? Because I'm under the impression I witnessed otherwise 1-2 years ago. Not sure I remember seeing any cases where this would factor in lately, though, as I haven't seen city sieges or murderous settings myself in a while.