ASW – Alternative hero leveling.

The uniqueness of a racial skill lies in the fact that there is no normal choice? I thought the uniqueness was that it's common to all heroes of the race and always available at the start.

So what's the problem? Just make the connection from one or another beneficial perk a requirement for this racial skill.
It's both a racial skill (unique, tied to the race) and a mechanical one at the same time. Therefore, it can be placed in both categories. But from the perspective of streamlining, it's better to have it in the racial skill category.