If Jews were half Levantine and half northern/central European would they still stand out in Europe?

[Borealis]

As opposed to half Levantine half southern European(Italian) as they are now?

[Bellbeaking]

Most certainly not.

I may be wrong but afaik modern levantines are south shifted compared to the Roman era due to lower SSA and other more southern components. 1/2 Roman era levantines 1/2 north euros would probably look well within european norms but with quite a large range, and they would have a higher rate of light eyes and hair than modern south euros.