I've been looking at the Name files and it seems to me that while the CoreNameRuleset.xml was probably meant for new Sovereigns, it is not being used. WorldNameRuleset.xml is used for New Sovereigns, New Factions, New Cities (Past the defined ones), maybe other things...
Would it be possible to enable CoreNameRuleset.xml? Doing so would really improve immersion where Sovereign Names are concerned. Right now, creating a Sovereign NameGenerator creates issues as it's being used by Cities/Factions/Sovereigns and usually the first two are quite different from the last one.
LH Mods by Primal