At that time Amardi were de facto nominally subjects of the Seleucidae, we don't see any mention of assistance being rendered to them, nor even any complaint were being sent by Seleucus IV against unprovoked aggression of the Parthian monarch [REF].
Parthian aggression was checked as long as Rhages remained in Seleucid possession, and Rhagiana along with rest of Media, and the other provinces were safe.