the Emerald City of Oz
The defensive settlements of Oz seem similar to the Ebionite villages of refuge. That's where people go who seriously can't get along with others. If there were a different village for each of the main Ebionite antisocialites there would be six. One each for Taboo breakers, the Disrespectful, Murderers, Adulterers, Thieves and Liars. People who have bad intentions. Apparently there are very few people who have bad intentions in Oz. Other than the occasional cannibal or self centered loner everybody in Oz appears to have good intentions. Just some of them go a bit too far. Their good intentions become obsessions. Those who are obsessed with care for themselves or others are sent off to Flutterbudget Center and those who are obsessed with clear communications go to Rigmarole Town. Both have good intentions but a lack of common sense.
Also similar to the Ebionites is that Oz is one family and the head of the family owns everything. No one is poor and no one is wealthy because each has all that they want. With few exceptions the Ozites are all peaceful, kind hearted, loving, merry and sharing.
Ozma doesn't defend Oz from the invasion because they can both out fight and out magic anything she or Glinda has got. As it turns out she acts like an Ebionite Defender. That is, she brings them back on themselves. The Ebionite Defender can't be beaten because they turn the attack back on the attacker. A single Defender attacked by a bunch of folks with swords will simply strike provocative poses (possibly with a sickle made from the jawbone of an ass) and the attackers will clumsily manage to stab one another and themselves. To the extent they are intending to kill the Defender, they will kill themselves. In theory anyhow. And of course no matter how magically powerful the Phanfasms etc are they can't beat Lethe water. Or as the Chinese call it, Mama Wang's soup.Because the requirements for slaughter for meat are so stringent, the Ebionites don't eat much meat. Except for a few ritual occasions a lot of them were vegetarians. I notice that in City all of the described meals contain no meat. There's some dairy, but then the butter, milk and cheese might be vegetable as well. Though I do wonder what the lady mosquitoes eat.