2. Oded Fehr
This Israeli actor is the most likely candidate. Like Jason Isaac, he has already voiced Ra's, in the animated series Young Justice. Fehr has been a go-to guy for mysterious warrior since his big break in the Mummy in 1998. He has the background and the look to portray Ra's al-Ghul. At 6'2 he would be an imposing physical challenge for the Arrow to come up against. However, he looks a lot like Deathstroke actor Manu Bennett. Assuming Arrow dispatches Slade Wilson this season, it might not be enough of a change to go right to a similar looking Ra's.