How closely were the royal and Bardock's family related?

[Koitsukai]

Saiyan population consisted of only a few or several thousand people, they seemed to have only one ethnicity or race, so it's fair to assume they were somewhat related to each other; there weren't that many of them and they all looked like one another.

Considering that a few millenia ago we all shared a common ancestor, and even back then there were millions of people, way more than the saiyans ever, how far removed from each other could Bardock and King Vegeta have been? or Bardock and Paragus? or King Vegeta and Paragus? or Bardock and Turles' father?
Could any of them share a great-grandfather/mother? could Goku and Broly actually be like third cousins? what about Bardock and his team? Could they have been a squad of cousins, or at least some of them be cousins?
I mean, there weren't that many saiyans for them to be so far apart removed from each other, right?

I know there's something in Vegeta's lineage that must've been exclusive because of all that royal blood thing, and unless they screwed their sisters (shocker, right?) they must've mated with commoner female saiyans.

Obviously, they didn't care about their very own direct family members, so in no way I could expect them to give a fuck about a far removed cousin that would've been more of a threat than family, but that doesn't mean they couldn't have shared ancestors.

[Grimlock]

Maybe closer than we think. Toriyama said Bardock might have had siblings, so you can always assume one of them is directly tied to Vegeta's family.

In fact, coming to think more about this, I will have that assumption from now on. Goku is indeed related to Vegeta, and it's just as "shocking reveal" as that new Harry Potter fan coming to realize that Harry Potter and Voldemort are cousins themselves.

[Bloodthroe]

There is really no telling. Toriyama said in an interview that Saiyans don't have strong family ties outside of the royal monarchy. He went on to say Bardock and Gine were abnormal for being loving parents. It's safe to say Saiyans largely ignored their direct families and likely hooked up with other saiyans, not knowing if they were cousins or not.