>>96341820
The closest in the HH would be human operatives like Malcador's Yasu Nagasena (a literal fucking 30k samurai), or the assasins in Nemesis. Or the imperial cultists hunting traitor astartes in the Siege of Terra novels.

Otherwise, the HH didn't leave much room for meatbags among Astartes and Mechanicum murder robots. Most relevant humans were generals or ship captains.