Why is Orcadian so prevalent and how much is still wrong with North-West European Admixture?

I started my journey going through a lot of effort trying to map my family tree and can now conclude from my own research that the majority of my ancestors until around 1700 (some lines date even further back) have lived in the Netherlands, primarily focused on N/Z Holland/Utrecht and the northern provinces, with a few exceptions from Antwerp and North/West Germany. I was still curious about the lines that I could not trace and I tried a DNAtest at MyHeritage to see if anything else would come up. And it stated I was 100% North-West Germanic, which seemed pretty fair lol.

However with the new version now online, I got estimated to be 77.4% Dutch, 11.4% Danish, 7% German and 4,2% English, which made me curious if the strands I was not able to fill might be the Danish part as I had not found any lines to the Danes, only the Germans. This is still all plausible, I also know there is some Danish DNA mixed into our northern pool, until I started using my DNA on a few other platforms.

For a while I've been interested in the idea of Ancient DNA, as I'm keen to learn more about everything pre-1500. So when I tried out MyTrueAncestry, knowingly taking all information with a grain of salt, something peculiar showed. The highest estimations all ended up being West-Norwegian and Orcadian, followed by germanic tribes like the Longobards and Chaucii. There were even two early medieval remains (1 Norwegian and 1 Danish) that had huge amounts of similar data. And even now all data showed the same: Germanic, in addition to some Celtic/Pict and other North-Western cultures.

Getting more and more fascinated, I started using multiple Admixture tests that are specific to European DNA through GEDmatch. And to my suprise they all stated Orcadian and West-Norwegian to be way ahead of all the others even though these were not tied to the archaic DNA samples of MyTrueAncestry. Orcadian/Norwegian/Danish and English had distance approximations of 3-4, followed by North-Dutch on 6. To my disbelieve, South-Dutch and French were tied at over 14, which seems very weird if you know about the long history of France/Belgium/Netherlands.

Now to get to my point, are there any Dutchies out there getting the same results? Can these results become more reliable by actually comparing Modern DNA samples to Ancient DNA samples? Are there any good reads on this phenomenon and how it ties to The Great Migration? Doesn't this seem a little shady atleast, or am I reading into it too much? Or perhaphs I have to rethink my own Genealogy and tree?

All information on the subject is very much apprecciated and welcomed. Thanks if you made it through the long read.