Talat's hitting style is that of a middle order player. Openers are expansive strokemakers that play on top of the bounce which he doesn't.
Hammad does have hitting ability but he's quite vulnerable against quality bowling, particularly against spin. Even against pace, his feet don't move much and he needs the ball in his zone to hit. He won't get that against international sides. Because he doesn't offer anything with the ball, he's simply not an option.
Wow that's a pretty detailed analysis on the basis of a handful of international appearances. Maybe you should become a talent scout for one of the PSL Teams!