Ok, so you're really not going to comment on the fact that the guardians are literally clones of themselves and therefore have no discernible origin? That doesn't even faze you? ...You're going to do well in this comic :)
I had kind of assumed that they were clones of like, natural born people, but then I guess they showed up via meteor like the kids, so…But that would mean that the whole Sburb thing was set up like at least 100 years prior (since baby Nanna, I think, was shown as first appearing in 1910). And that it was already set up who would end up getting through the bombardment and nobody who wasn’t related to the guardians had a chance.
Also. I’m really used to stories like this that are so poorly written that those kind of plot holes are normal and not worth pointing out. I guess I should stop thinking that way, eh?