False analogy. AFAIK, Tyranids don't exactly have the same level of intelligence as humans and any similarities between both situations are due to different causes.
Nids have that one hive tyrant bloke that is continually reincarnated and retains all the memories of its previous lives whilst hormagaunts without guidance are like wolves
Some are smarter, others are not
Like humans
Except that most Tyranids aren't sentient which forbids them from forming groups without leadership from some psyker creature, and even then they're limited to it's intelligence, which is still fucking dumb in most cases, while humanity proved that they were more than capable of forming solid governments without Emperor, as the Warp travel without Astronomican is possible, even if pretty hazardous and much slower.
Read up on this, it's pretty cool, even if the creator picked only few theories.Except no. The Primarchs were genetically engineered from Big E own DNA and each one them made for exact purpose, which was imprinted in them so hard that even when they were raised in random environment they still defaulted to the task Emperor planned for them. Chaos Gods just think they did it because they fucked them around which was partially responsible for what they would become in future. Also because they're dicks.
Except maybe. Chaosy fellows during the horus heresy with Lorgar say Big E was given power by the Chaos Gods to make em.
You'd trust Chaos, wouldn't you? :D
Chaos? Maybe, Chaos Gods are usually pretty honourable in their own wicked way, but... not fucking Lorgar. He is the most manipulative, deceitful, and purely evil hypocrite this side of Universe, except maybe First Chaplain Erebus which was his most trusted sidekick and the guy who basically single-handely caused that world went to shit again, just because he felt like it.
Black Library canon says the Primarchs were made with a mixture of science and sorcery, the latter of which is supposed to have been stolen from the Chaos Gods in some fashion, hence them being irritated by the whole deal enough to send a Chaos Marine back in time to destroy the Geller Field protecting the infant Primarchs from the Gods. To some extent they consider themselves the real fathers of the Pimarchs, though it's possible this is just them being the lying bastards they're known to be.
Except canon in Wh40k literally doesn't exist. And Chaos Gods are angry that somebody is using magics without their allowance because their overinflated ego makes them think everything comes from them despite that they're just really angry little teenagers that make things happen with their minds. Also, hell, even if they're somehow right for once, it's still cool because Emperor knowingly fucked over four beings of immense power for the sake of humanity. It's a fucking Prometheus all over again.
This... isin't exactly true. The Emperor COULD be Chaos God of Order in future, right now there is a single, little, thing that stops him from being one, which is His own rotten body on the Golden Toilet. To be a Chaos God he would have to be an completly Empyrean (Immaterial) entity. Right now he's just the most powerful psyker ever, with power that rivals Chaos Gods and that puts his future in Warp in pretty good light, as there won't be anything powerful enough to mindfuck him and eat the remains.
That's just one possible outcome, others include nothing but bad times ahead of humanity. And if he did become Chaos God? He wouldn't be the "Chaos God of Order" (unless everyone in the Imperium became bureaucrat commissars) he'd probably be the embodiment of Chaos Undivided: The Man Emperor of Mankind
Well, not much would change really. The existence of Chaos Gods don't exactly make everyone turn into rage-fueled sex machines manipulating people to spread space AIDS. As for the Chaos Undivided - a lot of people mistake the terms due to fucky naming. The Chaos Undivided of Malal (which, funilly enough, is theorized to be the missing Primarch (as in, fucking man made God) of missing XI Legion. His sacred number is XI, Sons Of Malice (aka the CSM that follow him) center their rituals and trophies around the number XI too, and those guys own too much of pre-heresy stuff to be just some random marines that went renegade sometime after HH), which is basically Chaos God Of Chaos (as in, anarchy) which is basically being random as fuck. There is also the "Neutral" Chaos Undivided which is basically doing things for your own reasons, which would be closer to Man Emperor of Mankind, but still...
Anyway, this is all bullshit theories because we all know that what truly will happen is that Orks hijack the Golden Throne and use the WAAAGH effect to heal the Emperor so they can have da bigga and badda Boss in da univershn.