In my opinion, no fighters are scared at another one you know...it's just the game of "what is the money if I fight this guy". Hell, even during Tyson era, the opponents were making queue to fight the "most dagerous man". :D
Vitali would have crushed Rhaman, I can see a battle of jab for four rounds, then ater that vitali connects with his right hand, the brave rhaman would be put into sleep.