No. Blowing up Suleimani with a predator drone was not an assassination. No. Blowing up Saleh al-Arouri with a drone was not an assassination.
Assassination requires a scheme or subterfuge. It's creeping up on someone or setting up for the perfect moment. An entire military department directing a distance strike at a convenient moment is not an assassination, it is an act of war.
Assassination is ALSO generally an act of war but the method and context is different.
I fully agree. An assassination requires at least some uncertainty about the culprit. A missile that kills 9 innocent people and one target* that you take full credit for is an act of war, not an assassination.
*The target is also almost always more innocent than every person involved in the strike.