Love the idea of this though if it helps, the area of the modern region of Saxony - the parts that were a part of the original Saxon Realm we could call the outer realm with the remainder being called after it's original name of Thuringia. But now we will need a name to seperate that confusion. How about Saxony means the original region and the other South Brandenburg?
Aside from confusing repetition names at least we no longer have the widespread mixed use of Dutch for those of the Netherlands and Germany anymore in English apart from talking about the Amish and the sort. Great idea
@Gukpard, I love it enough to overlook you calling us Celts haha. Saxnot mid us!