Is the obedience cause compatible with Gruesome Strike and/or Instrument of Slaughter?

According to the text " Prerequisites: champion’s reaction that grants extra damage with your Strikes (including the desecration, iniquity, and obedience causes)", it calls out that obedience cause, but the obedience cause doesn't grant your Strikes extra damage' it grants you Iron Command, which forces someone who has struck you to either fall prone or take mental damage. Am I missing something here?