If I had to guess I would say whoever was waiting to transport the assassins out after the hit killed them. Why trust that many guys on such an important hit? Let them do it and ambush them while they are only worried about "getting away". Would be my guess.

I don't believe the Roth hit was a why to get back into his good graces.

I will have to look again about the necks of the assassins. Never noticed that.