This is great point which you mentioned about Afghanistan cricket team lineup. Their team relies on few key batters which means they win big or lose big. Having too many all rounders as you mentioned can be problem because they are not as good at batting or bowling as specialists which makes team less consistent. In contrast Pakistan with more dedicated batsmen has more stable and reliable foundation. Your analysis is good for Afghanistan to become top team they will need to find better balance in their squad and rely less on all rounders.