Trajan
Veteran
He has good contacts with the Saudis (even met the Clown Prince last year). He is disliked by the Iranian government and clerics as an unreliable and unthankful lunatic.
Yh I don't see how this a W for Iran. Saudis were backing him because he's an Arab nationalist and not an Iranian puppet.
MBS was trying to lure him into Riyadh’s orbit. Al Sadr is known for propagating Arabness and the Iranians don't really like that. Saudis would prefer pro-Arab Shia to a pro-Iran one.