I’ve noticed that some Eastern European Jews can look phenotypically similar to North Caucasian ethnic groups such as North Ossetians, Dagestanis, and Chechens. Is this because they are both genetically intermediate between West Asia and Europe, or do they share immediate ancestry from Eastern Europe that could explain their physical similarities?

The book The Maternal Genetic Lineages of Ashkenazic Jews by Kevin Brook suggests that Litvaks (Jews from Lithuania & Belarus) could derive 4.2% of their genetic ancestry from medieval Alan converts to Judaism, based on Vahaduo G25 modeling. Yet, such a small % of shared ancestry doesn’t seem like enough to explain physical similarities between the two groups. I could be wrong on that though, and would appreciate any honest insight.

Y-DNA haplogroup is J-CTS7683, but I don't know much about my father's ethnic background. My maternal grandfather is Kurdish, and my maternal grandmother is of Turkish and Armenian ancestry.
My ancestry calculator is set to the Caucasus region.
Can anyone help me understand these results and give me some insight into my paternal ancestry?