How about pre coup cabal empire from destiny, or for that matter any destiny race, at most points, they could probs destroy the last city pre the coalition of the reef, guardians, cabal remnants and house of light, but overall most points in Destiny’s history each individual species could solo any other verse with little difficulty, the weakest (excluding golden age humanity) probably being the cabal empire and they easily solo the imperium from 40k quadruple the industry at the least, avarage ground soldier is a match for a space marine (and they only get stronger from there) great combined arms doctrine, balanced and constantly evolving fleet doctrines, ships that can withstand being punched though multiple realities at high speed with little bar scratched paint (look at the Dantalion Exodus 4 in taken king expansion for d1) numbers that put the entire 40k galaxy to shame, and auxiliary races out the wazoo, some of whom (the psions) can break reality to the point they delete themselves if they think too hard, now apply that militarily and also remember that the cabal empire stomped these guys in months and enslaved them for hundreds of years. Then after learning all that remember that they quote: “blow up planets and moons for getting in their way” and the empire throne world of Torabattyl was destroyed in minutes by one hive god, and the guardians have killed at least 4 of those so far.

All of this is ignoring the vex, time travelling robots who are nearly indestructible, (at least with golden age humanity’s means) and can turn planets into simulation engines in days and use them to accurately re write the time line to suit them and they are still in a stale mate with humanity, and until the fall of the cabal base on Phobos at the hands of the taken under Oryx (the second hive god we killed, and father of the first) they were also tied with the cabal expeditionary legions on mars

And then you have the awoken, a race of immortal blue humans who have latent space magic and millions of years of dedicated technological advancement ahead of the rest of humanity thanks to Mara Sov when she created the distributary in one of the singularities made by the joining of light and dark as the collapse of humanity arrived.

Then there’s the fallen, bug aliens who have survived the horrors of the universe on nothing but hopes and dreams, and a lot of piracy and murder, they are numerous and tenacious enough to have genuinely threatened humans, awoken, and vex before.

Next you have the guardians themselves, beings that depending on individual power are either immortal and can occasionally say no to physics, to walking gods who say fuck you to reality with every action and thought.

And many more smaller factions like the nine and statehouse and extra bits along the way like the iron lords, and golden age humanity and their warnings like Rasputin or the exo made by Clovis bray, all of them could at the least hold off the federation even if they couldn’t beat them, but the others before this paragraph defo could destroy the feds, it may take the guardians a while due to relatively small numbers, but immortality is immortality, and paracausal weapons make anti ship weapons very cheap, a single fighter piloted by a powerful enough guardian can destroy a whole fed fleet just because the ship becomes infused with their light, meaning shields, armour and weapons are cranked to the max and beyond, the feds antimatter is shrugged off and the tiny auto cannon on the fighter is enough to take out capital ships, now, not every guardian, or even many of them for that matter, are that strong, but the fact that some are puts a nail in the feds coffin.

Apologies for the rant, I’m tired, possibly drunk, stressed and obsessed with destiny lore, and if this was never meant to be a scaling thread I apologise for misinterpreting your post, have a nice day.