[SsSam]

I believe making them potential random events would give more deniability than letting one or two other nations in the same age cast the spell.
You give Tupilak's to LA Mictlan and it doesn't help Atlantis deny culpability if Mictlan isn't also in the game.

For what it's worth I've had non-merc assasin Ninjas come after me when I was playing as Joman and I know I didn't send them myself.