Mixing Pumilio Import Years

I can't sleep!.....I've been lying awake pondering what Pumilio locales can be mixed/interbred stemming from different import years because their habitat has no geographic, topological, habitat type, etc barriers?

For instance, I saw reputable opinions stating that the Escudo years can be mixed. The rational generally was because the island has relatively homogeneous environs. Is Escudo the outlier in this instance?

It sounded like the jury was a "no" on mixing Neighbor's Salt Creeks with the 2012 Salt Creeks.

Many pumilio that have been in the hobby for more than a decade such as Bastis, El dorado, Chrsitobals typically are advertised without year of import....

Is this issue a no go on all mainland locales? What about the other islands...ala "yellow belly" vs Cayo de Aqua.

Are there any locales that are so small that different year imports essentially have to be from the same areas?

It would be nice to know which locales can be mixed from different years. Does anyone know for sure?


Thanks,
Sleepless in So Cal