GoC wrote:1000 humans waaaaaay is too small for civilization. Make it 100 million humans vs 10 billion Neanderthals. My guess? Humans. Even without specialized weapons they still have durable cars and various explosives. They can wield metal plates on a tractor and make a flamethrower. Fried Neaderthals!
Really, saying "The zerg beat the Xel'Naga so they MUST be really powerful." is rather silly. The Federation might have beaten the borg and the dominion but that was 100% deus ex machina and overwhelming borg stupidity.
Well, if all 10 billion Neanderthals were in a position to surprise attack the 10 million humans in a span of minutes to hours I think they'd win. I think that another major factor is that the Xel'Naga are all in spaceships - in theory all the Zerg had to do was launch a surprise attack and knock out the life-support systems. It would still be a stretch, but it seems plausible that they might win (ok, about the plausibility level of the Enterprise defeating a Borg cube).
Yeah, I don't think it's a good establishment of how powerful they are in general. It's pretty analogous to the Federation defeating the Borg. For both the Borg and the Zerg, if they really acted as powerful as they are supposed to be in theory, they would easily dominate their respective galaxies (well, I guess the Zerg kinda have...).
If thrown into all out war at current levels of strength, the Borg would win simply because the universe they're in is at a much higher level of technology (and incredibly vast compared to the Koprulu Sector). But since that would be so one-sided as to be boring, let's consider who would win if both were given ample time to evolve/adapt and assimilate/infest many species. At the very start, I think it's fair to say that the Zerg could evolve attacks to penetrate Borg defenses - after all, Species 8472 creates incredibly power energy blasts using purely biological ships (not that the Zerg would become that strong, just that in principle biological weapons can be as devastating as mechanical ones).
In terms of general method of operation, it seems like each side has advantages.
Borg: it's much easier in general to achieve high levels of power through mechanical technology than biology (energy weapons and shields, tractor beams, transporters, etc.), and obviously their ability to adapt to attacks is very powerful.
Zerg: they are extremely prolific, and I think it's fair to say that they apply more creativity to their adaptations than the Borg: the Borg adapt to be immune to a very specific attack (down to the exact frequency of an energy blast), while the Zerg Overmind can use the sum total of assimilated genetic data to mix and match features and create unique creatures.
If it was a war to complete annihilation I don't think either side would win. I doubt the Borg would ever be creative enough to develop the psionic weapons required to destroy the Overmind (if they ever became aware of the Overmind's specific existence in the first place), and I think the Zerg could spread faster than the Borg could wipe out planets. The Zerg could probably keep evolving varying forms of attack to counter Borg adaptation, but having to do this would slow them down, and so I doubt they could ever really destroy the Borg while having to constantly regroup and evolve new attacks.
If either side did win, it would probably be after consuming the majority of resources in the Galaxy, and thus the "winner" would soon die off too.