I understand that "League of Assassins" are supposedly the bad guys and no matter their philosophy, it usually ends in destruction of lives. But hear me out.
Arrow was, in Ra's own words, "one of the greatest students he ever had" and with confidence, he was ready to pass down the throne and the privileges that come by it. Oliver of course, had a different set of philosophies not aligned with the League, hence ultimately chooses better off from it.
But isn't the philosophy of the League the philosophy of the one who is leading it? Ra's mentions as much. Imagine all that Arrow could've done with a league as capable and powerful as the Shadows. Even if he chooses not to make use of it, he could've simply disbanded the league to ensure it wouldn't fall to the wrong hands. I still feel, giving away the ring to Malcolm was a highly irrational and even a dangerous decision. Is there a good reason why he didn't become Demon Head?