Look, we all revere early Islamic civilisation for its superior philosophy and form of governance for the time it was in. To say that you simply advocate that sort of organisation at the government level leaves a million and one unanswered questions, and to leave it at that is to deny the reality of the modern world and its complexity.
For example, in your ideal of the first state of Medina, a city state with a constitution. By whatever you might discern from studying it, what political structure would suit Pakistan, a country of nearly 200 million, various provinces, cultures and many cities (not a city state)... Centralised or decentralised authority? Provincial or federal allocation of resources? Would you have a republic, federation, parliamentary system?
One can take inspiration and guidance from the Islamic ideals, but attempting to apply them to the modern context without significant expansion would be bad. Most successful nations on earth got there by having robust and modern political systems, not idealistic ones.