I personally don't mind if it is prior to them being "officially" dubbed the Assassin Brotherhood, since they have had their principles since their inception as the Hidden Ones. Same for the Templar Order existing earlier as The Order.
What I most enjoy in Assassin's Creed is seeing how each group and its members seek to put their principles to practice in the society they operate in, and then seeing how they try to dismantle the others' work thru espionage, sabotage or outright war.
