"Guerrero" is a common last name in Spain.

How did you come to that conclusion? The last name Guerrero predates the 1500s by centuries.

Why would the last name come from him and not the other way?

There's that lovely phenomenon, I can't recall the name, of people that live to their name. Like a cook who's named Jon Cook, a gardener who's named Phil Gardener, you get it.

So this.

nominative determinism

It's name itself serving as a kind of fate for what it refers to

Is that "bootstrapping"?

Well, it may surprise you to know that surnames such as "Cook" and "Butler" are occupational and actually derive from men, centuries ago, who were actually cooks or butlers and eventually coined a newfound surname from that occupation (which may often be passed down father-to-son.)

So if a modern fellow is named "Jon Cook" it may indeed be a regression hearkening back to one or more of his ancestors and how they were named.

I am more accustomed to "nominative determinism" being associated with a person's given name, and how they grow up to take on a given role.

Perhaps this example:

https://www.bbc.co.uk/news/articles/c078l0glxg8o

Or a librarian named Mr Bookman.

"Guerrero" comes from Spanish "guerra", which is cognate to English "war". They both derive from a common proto-Germanic root.