The line is a bit more blurry on the East side than the West but this might just be my own bias coming from Lebanon.

I always thought Urban Hejaz and the Levant [and Egypt] share in a dialect continuum or at least a sprachbund, I don’t know a lot of dialects that say مرق to mean pass except those two. Urban Hejazi dialects also drop the use of interdentals like in Lebanese. In the same way Bahrani dialect Bahrain/Eastern Saudi Arabia shares with Mesopotamia in having Akkadian and Aramaic influences.

Here’s a fun comparison between Hejazi and Najdi dialects https://youtube.com/shorts/Fi9_bNiazOA

More aggressive in tone on average.

Only the Bedouin and Najdi dialects which happen to be over represented. Jeddawi in particular and other Urban Hejazi dialects are seen as effeminate https://youtu.be/AHWbA0b9bK4