But you also have to factor in Oolong and Puar. They can achieve human form for varying amounts of time (Oolong is 5 minutes, Puar is seemingly endless). Who's to say that they don't copy the entirety of human body structure as well? Meaning that technically, Goku/Vegeta could in fact fuck either of those two and produce biological Saiyan descendants. Considering their transformation skills as well, you could also get Saiyans with the ability to morph for various periods of time. There are of course other factors as well. For example, why not wish that Goku/Vegeta were hermaphrodites and therefore able to increase possible partners. Or if you don't want to go into the lewd direction, you could wish for them to become cloned, therefore increasing the population as well. Of course, we aren't entirely sure if Shenron has the ability to create life from nothing, if he did however, (Or Porunga or any other Dragon) you could in theory wish for their to exist, let's say 1,000,000,000 female Sayians, therefore creating a eventual utopia and as such, repopulating their race. Of course, pregnancy would be an issue, considering that only two people are allowed in the hyperbolic time chamber at once. You could in theory just send them in their for only a portion of their trimester, but it would just result in a disorderly mess. As well, did you factor in the alternate dimensions Birus alluded to in Battle of Gods? For all we know, there may be multiple versions of the same Saiyan species around the multiverse, just waiting for the Dragonballs to be used for interdimensional travel. This opens up a massive amount of theories, but this post is getting ramble-y as it is, so that'll be for another thread.
In short, Dr. Slump is the better series.
(In case you seriously couldn't tell, that whole post is a big old pile of /s.)
and if you count GT's balls..
