Another interesting point which could partially explain why Oliver got his ass kicked....
Apparently it was Ra's Al Ghul who trained him (the guy who trained Batman and Bane), plus his method of training would have been better than Oliver's, especially considering that they trained under completely different conditions. When you think about it, his plan to level the Glades is a very "league of shadows" thing to do......
Also, Malcolm took of when his wife got killed for 2 years, however, no doubt trained throughout the years (18 years) so actually he would/does have more training