They were the ISIS of the Ottoman Empire of 200 years ago. They terrorized the region and killed thousands of shias.
The issue with governance is that consensus on the path of Allah is required in obedience to the ruler who establishes the guidance of Allah best - unless he is proven beyond doubt to be a rebel against Allah and His messenger and must therefore be removed from authority and replaced with someone better and best suited for the role of leadership under Allah.
This in turn requires that all who fall within the boundaries of the genuine Islamic State must relegate their authority to it - otherwise it risks becoming more like a chaotic, weak, and teetering karzai government with no credibility or real authority to legislate.
One of the main points of the second pledge of Al-'Aqabah was the monopoly of the Prophet
to command within Allah's obedience and to be obeyed. Therefore people need some sort of general consensus within the limits of Allah in order to be able to run a state that is not in turmoil; on the brink of collapse from mutiny; or at risk of external invasion due to it's occupation and expenditure of human and material resources on internal problems.
On arriving in al-Madeenah, a treaty was signed (along with other stipulatuons) with the Muslim leaders of clans to hear and to obey within Allah's limits, and with neighbouring non-Muslim clans to run their separate governments, but to be ready to assist each other in the event of an external attack whilst bearing their own costs, and to allow the Prophet
to settle any major disputes which may turn up amongst them - this sounded like a very cohesive government with stability and the ability to advance positively whilst making sound deals and treaties outside of the state.
وَإِن طَائِفَتَانِ مِنَ الْمُؤْمِنِينَ اقْتَتَلُوا فَأَصْلِحُوا بَيْنَهُمَا فَإِن بَغَتْ إِحْدَاهُمَا عَلَى الْأُخْرَى فَقَاتِلُوا الَّتِي تَبْغِي حَتَّى تَفِيءَ إِلَى أَمْرِ اللَّهِ فَإِن فَاءتْ فَأَصْلِحُوا بَيْنَهُمَا بِالْعَدْلِ وَأَقْسِطُوا إِنَّ اللَّهَ يُحِبُّ الْمُقْسِطِينَ {9
If two parties among the Believers fall into a quarrel, make ye peace between them: but if one of them transgresses beyond bounds against the other, then fight you (all) against the one that transgresses until it complies with the command of Allah; but if it complies, then make peace between them with justice, and be fair and just: for Allah loves those who are fair and just.
