It is amazing how no one learned from Ordenstaat that (Rettle/Twain)ville is a pretty sub-optimal place for a realm. It requires nearly constant babysitting from its neighbors, while their neighbors face similar problems.
Sometimes I wonder if certain parts of Dwilight weren't intended never to be secured by human civilization.
I suspect one of the big problems (among many) is the fact that there is no townsland around the city. This means less gold -and more importantly- it cannot support palisades.