Best way for nation-specific pretenders/monsters

[Psientist]

What is the easiest/ preferred / best way to declare a nation-specific pretender/ monster for more than one, but not all, nations? Particularly relevant if you want to create a pretender for all ages of a given nation.

Method A: Define once, then "copystats" that pretender multiple times (inelegant).

Method B: Completely define the pretender from scratch each time (very inelegant).

Method C: Define once, but declare multiple "restrictedgods" (I don't think this even works)