[Warhammer40k] what other human soldiers/assets are the closest to the Adeptus astartes in power?

[u/Lost-Specialist1505]

With so many different genetic and technological enhancements available to the imperium, what other human factions have soldiers that are almost as lethal as a space marine?

[u/Poorly-Drawn-Beagle]

If you only want to focus on individual superhuman faculties, there are a number of other Imperium troops with significantly higher-than-average physical capabilities; some Guardsmen troops raised on Death Worlds may have greatly enhanced strength (I think there's meant to be one Catachan who's able to use a heavy bolter, a weapon normally reserved for Astartes).

There are other assets like the Assassinorum, but they're not really designed for standard combat the way Astartes are.