Now that I think about it, is it possible that all the realms started off as merged and then broke apart to create the realms?

That would explain how the same races exist in different realms. Like snakes look like they belong in China and so do the dragonians. Theres dragons in Ninjago and in the first realm. Humans exist in like 90% of the realms. Realm of monsters and the underworld have beasts that look similar.

And the fact that the life dragon said that Lloyd was supposed to do his trial but the whispering woods wasn’t a place in the realm Ninjago was in. If the realms started off merged then it would also explain how there was multiple green ninja without it being written anywhere.