In fact those cupolas, take the onion shape the tartars used on their heads. (turkish turban style)If they were European Jews, they could have been from the Askenazi branch of Judaism. These Askenazi Jews originally came from the Khazar kingdom, an empire in the north Caucasus region between Europe and Asia lasting from the 7th century to the 11th century whose leaders adopted Judaism. That would explain both the influence and the cultural choices of temple style. The Khazar region is part of what this site refers to as the Tartara people that disappeared from the history books.
Onion in russian it's LUK.
Lukomoryie (Tatar Lands)
Lukomorye - Wikipedia
Jews and Arabs was the same a few centuries ago.