The Uploading Guidelines states this exception under Humans and e621:

If a page, or an image, of an otherwise furry-centric comic contains only humans, then those pages will also be kept to keep the comic complete.

^{* This has happened to my uploads before (ex. post #4067858 in pool #34331), and I know pooling these makes it easier for these posts to have their context associated and not get mistakenly deleted (like some in pool #40661 once were).}

This exception is made for comics because they are sequential, but could the same exception be made for a collection of model sheets that preface a comic but aren't events within the comic itself?

I'm asking this because the master posts for two alternate universes of The Amazing Digital Circus I want to post, The Amazing Digital Carnival and The Terrible Digital Circus, contain character bios to show how the characters are portrayed and designed differently, but some characters like Pomni, Ragatha, and Kaufmo are ostensibly human.

Could I post them all in a pool without the human only ones getting deleted, or would I have to compile it as a third-party edit so its all together? (like I once did with post #4067831)

Well, splicing images together to try and get past relevance standards is a pretty big no-no, and frankly that past one probably shouldn't have been approved. Third-party image splicing should be avoided as often as possible unless it just makes sense to do it.

As for the relevance bit, I think you could potentially make an argument for it as part of a pool, if it is created in association with the pool as supplemental materials. I dunno if that's enough but I think it could be worth asking about.

recursion said:
Well, splicing images together to try and get past relevance standards is a pretty big no-no, and frankly that past one probably shouldn't have been approved. Third-party image splicing should be avoided as often as possible unless it just makes sense to do it.

Oh. Well good thing I only did it that one time. I haven't posted many third-part edits, and the only other one made by me was a textless edit, post #5014046.

I'd argue it made sense though, because those two characters were made as a duo and appear together in all posts but that aforementioned post #4067858.

recursion said:
As for the relevance bit, I think you could potentially make an argument for it as part of a pool, if it is created in association with the pool as supplemental materials. I dunno if that's enough but I think it could be worth asking about.

Supplemental materials... So you think it might be okay if I posted some of the comics and had the bios as a prologue of sorts?

As Recursion said, splicing image edits is usually a bad idea. We'd pretty much always prefer the original version and in the best quality available.

If something is not relevant enough by itself, but it is part of a bigger piece that IS relevant enough, then those can be allowed. But they usually need to be added together to the same pool as the rest of the comic/image set/official artpack/etc so that everyone can see the bigger context for it. And the majority and focus of the bigger comic needs to be relevant enough to justify keeping the parts that aren't.

And to be honest, the majority of characters in both of those linked comics are semi-human and borderline relevant. For Terrible: Jax, Gangle and Zoomble are the most nonhuman, and Jax is the most fully relevant. And for Digital it's probably the same way. So your best bet would be to upload them separately but then make sure they are pooled. But even then, for in this case I'm not sure they are relevant enough to really keep. So I probably wouldn't upload them here at all. But maybe you could choose a different booru to upload them to instead? There are plenty of sites out there that welcome the more humanesque content that we don't archive here. So not being relevant enough for here, doesn't mean you can't put it somewhere else. So that's what I would suggest.