Hey there, have a cookie for this cool concept
There is a flaw in your faction list however, namely that 'Graafschap Hollant und Fryslan' is incorrect in several ways. Let me explain in detail:
1. Linguistically, Graafschap is Modern Dutch, Hollant is Middle Dutch, und is Modern German and Fryslan is Modern Frisian, so it is really just a completely nonsensical composition. The most sensible Middle Dutch translation of this would be Gravescap Hollant ende Vrieselant, but this is still not adequate, as this translation would much better fit the 12-13th century than the 10-11th century.
2. You apparently assume that Holland as a political identity already existed during the 10-11th century. This is incorrect. Holland was during this period part of the larger Frisian cultural region, and only became its own county during the late 11th century, the term Hollant being first attested in the context of a region separate from the Frisian region in 1101 AD. Indeed, Holland was during this period of time still very much Frisian in culture, Dutch (a Frankish related language) becoming more and more dominant from the 11th century onward, until it had completely replaced Frisian (a Saxon related language) in this part of the Low Countries by the 13th century.
3. You also seem to assume that Holland and Fryslan (or Friesland in Dutch) together formed a single county. As I have said above, Holland only became an independent county during the late 11th century, while at the same time, Fryslan was still divided into several independent counties. Indeed, in the 10th century, the whole of Frisia (to use the Latin name) was split into dozens of Gouwen (Gouw is synonymous to the English Shire). Each of these regions was ruled by a lord, called a Gouwgraaf (best compared to the English Shire Reeve, or Sheriff as it is now known), who usually wasn't very powerful on his own. However, the Frisian counts (and I'm including here the counts of the various shires that the later counties of Holland and Zeeland were divided into) did have strong ties of kinship, and there was a certain sense of common Frisian identity among them, so you could say there existed a kind of 'Frisian confederation' that spanned from Nordfriesland in the north-east, along the coast, to Zeeland in the south-west.
So what then, would constitute a correct name for the faction? I have already stated, that Holland did not exist as a consistent geographical or political entity, that the whole cannot be called a county, and that the dominant language throughout the region was Frisian during the 10-11th century. So I would suggest the Old Frisian term Frēslond Rīke. Looks familiar? It should, because it's just like your names for England and the Scandinavian factions. The Frisian language was and still is the closest relative of English, with their other close relatives being the Scandinavian languages and Low German (the latter being the direct child of Old Saxon).
There's a lot more stuff I could tell you about this and many other subjects, but I'll leave it to this for now, for the sake of your sanity. If you need any help regarding research (especially map research, see my DotS previews to understand why ), send me a PM and I'll see what I can do.