my read on it was that hashish means assassin, but not that assassins use cannabis. If one wanted to successfully carry out an assassination caper, I doubt that smoking pot beforehand would be a very good idea.
Hashish, when referring to assassin, refers to assassin of youth, it makes young people complacent and if they begin using cannabis at an early age and keep doing it, it basically kills their drive in life. Assassin of the Soul.
I say that because of all the people I've seen who used it, they've all ended up to be losers - empty souls. Most people who tried it in college eventually quit, grew out of it.
Of course that's just my experience and others' may differ. Those who smoke pot regularly will probably want to tell me I'm wrong.