Does anyone know whether Find and Harvest commands work on summoned NPCs?

For this minion mod I'm working on I want to issue commands to ANY summoned NPC, (important detail is these packages have to be added on the fly, they can't be added in the CS). My framework for commanding regular NPCs work absolutely fine, but the summoned undead I'm testing it on stubbornly refuse to follow any packages I assign them. It's not that they arn't using the packages, I can confirm the packages are present on them and not being overridden by another package, it's just they refuse to follow them.