Here are my views on Sohail Khan, I'll do Riaz later:
Sohail Khan
He is a well built, strong lad and this accounts for a large proportion of the stability of his action. Whereas his arms have the potential to go all over the place, he remains well composed. He runs in at good pace for a man of his build and keeps a good form in the run up to remain in control of his body.
He gets very high in the jump, which is good for a strong person shouldering the ball down. He throws the front arm out, at the target, very well. He generates pace from the front leg by throwing it to square leg and bringing it back down, like Mohammad Sami - credit to Goughy for teaching me this information about the front leg, btw.
He is very round arm in the action and this is fine, because it is the sort of bowler he is. This could mean that he could generate good reverse swing, like Waqar Younis - but I cannot accurately predict that. He follows through with the head facing the ground and the arms followed through completely, much like James Anderson, Amjad Khan or Graham Onions and this probably gives him some pace. If he struggles with accuracy, he should perhaps not put the head into it as much - but as shown by Anderson, it is not an easy facet to change. Good explosion at the crease too and he gets nicely side on.
The only cons is that his front foot closes off his action a tad, ala Matthew Hoggard which gives him outswing but may prevent an inswinger and cost him a yard of pace. His front leg buckles at the crease too (like me), which costs him height and means that his weight is diluted into the ground (credit to Ian Pont for informing me of this facet of the action). His front arm falls ever so slightly too early in the action, which means that his bowling arm is too far through the action when he lands and he loses leverage. This is so minor though that it would only cost him 3kph at most. I remember reading a correlation between delivery stride length and leverage so it may be a possible solution.