But what if some of the races that are considered to be close to their own kind had some kind of racial morale bonus when grouping with one or more others of their kind? It might promote racial identity a bit more. This could be either an inherent thing or even an edge for characters that have X many number of hours grouping with other characters of their own race.

Races that might benefit from this (ignoring that two of these already have similar benefits):
Cloud Giants
Storm Giants
Elves (High, not Dark-Elves)
Felar
Dwarves
Svirfs
Orcs

This (well, our version of it) was implemented as part of the original morale code.