Originally Posted by Gavinfoxx
If you are making a fake (but relatively authentic reproduction) fleet of Imperials from a lost planet, including soldiers and army, and a 'lost' astartes chapter, you will need at least several hundred thousand biped organic humans, transhumans, and abhumans.
In fact, if it had a variety of abhuman body types that aren't considered xenos, but are often considered 'allowed' stable mutations (ie, recognized abhumans), it might be a good way to introduce some societal change, to boot.
An unknown, but 'loyalist' astartes chapter living next to some fleet-based humans and abhumans of various sorts (this could also be a reason for why/how they 'lost' their navigators and psykers and astropaths), with PDF forces that contains a high percentage mutants that are similar in body and genetics to the other 'allowed' mutations (scalies, ratlings, the modern flavor stuff that is similar to squats [ie, high g abhumans], neandor, felinid, pelager, longshank, troth, etc. -- though they would want to have some excuse to stay away from the dumber types, like ogryn and beastmen)... if this group of transhumans, abhumans, and normal humans fought a successful Crusade against Chaos...?
Of course, this group would have to have some sort of archeotech that successfully helps stabilize mutations over time and can check for chaos-based mutations vs normal non-chaos mutations, which would allow this sort of diversity...
Just create a sort of distorted mirror of The Culture with Imperial standard technology and culture and what is 'allowed'. Strength through diversity and technology and such.
Of course, the Imperium might not just welcome these wayward children with open arms... but they are sitting on a ton of archeotech, so it would have a reason to make nice to them...
That's not a good plan.
First of all, the lie is full of ridiculous holes. They "lost" all their Navigators and Astropaths but are still capable of moving and communicating FTL? They have an entire Space Marine Chapter without a single Psyker, who refuse to donate their Geneseed to the AdMech for purification? They just happen to have a whole bunch of tech no-one has ever seen before which doesn't come from any known STC printout?
Secondly, that's a really huge complex operation to trust to a group of anarchists. What if some of the "Imperial Guard" decide they don't feel like following orders that day? Or if even a small portion of the population isn't comfortable with watching heretics and mutants burned at the stake, or supporting a society actively committing xenocide? One or two STC Agents could keep their covers, maybe, but I'm not seeing "several hundred thousand" Culture citizens being able to keep up the ruse.
Also, I keep seeing this idea come up and I have no idea where it's coming from, but Archaeotech is not the magic code-word for unfamiliar technology not being Heretical. Unless they're using tech the Imperium already knows about or they've got some STC printouts (or convincing fakes) they're going to be under some pretty serious scrutiny, and the AdMech is going to be on their case either way. And a non-Warp FTL is never going to pass for Archaeotech, because humans have never had such a device