The 50%+ area is not true for all areas. Tunisian Jews and Libyan Jews don't score very high European.
For Algerian and Moroccan Jews - Northern you go in the country more European you'll score. I think it peaks in Oran in Algeria and in Tanger-Tetouan for Morocco. There it's not extremely Atypical to score even 60%+ European with a significant Spanish (Conversos escaping to North Africa).
In the southern parts of Morocco you can find Moroccan Jews with only 20% European.
Take a look at this Moroccan Jew-
https://i.ibb.co/tC27DPB/Screen-Shot...1-58-33-PM.png
Although her surname is Toledano (Toledo=Sephardic)
On the other hand... This Algerian-Moroccan-Tunisian Jew is extremely European (Saw her picture, she also looks very much like North Italian to me.. very fair skin and blue eyes and Alpine features.. just she has curly hair like a good Jewish)
https://i.ibb.co/2K7zcdb/Screen-Shot...1-58-57-PM.png
Both are extremely Atypical.
I don't think it's possible to know how much European Ashkenazim would score on 23andme as they also mixed with other populations (possibly with even different types of Italians). I guess more than 50% (although the North shift to Sephardim is mainly because of some Germanic-Slavic mix and not % of European)
All I know is that in Israel Moroccan&Algerian Jews are considered "Mizrahim" even tho the distance between MJ to Ashkenazim is about 7-9 on gedmatch while the distance of MJ to Iraqi jews or proper Mizrahim is 30+++
About the Megharbi component, full Berber tribes converted to Judaism prior to the rise of Islam so I am not that surprised it's sometimes higher than the West Asian levantine.