I have treads upon stars with army of one. I came to Venus to do some bounties and broke it out for the sticky grenade bounty. And noticed it wasn't triggering when I'd kill goblins and hob goblins but would for harpies and minotaurs, as well as the fallen. I thought maybe they were being damaged by someone else or the other enemy so I went somewhere no one could follow and only with the vex. And sure enough, could not get it to trigger on goblins and hobgoblins but could on the harpy and Minotaur. Tried for a good while and with one hit kills so it was rapid, and unassisted. I like army of one for trickle so I'm surprised I haven't noticed this before! Thanks