unity historically has always come through force, one state/caliphate/empire conquered the rest and established a unified/organized system.
prior to the seljuks when there was too much multiplicity, and the arabs were constantly infighting, you had the same situation as today with the crusades and the loss of jerusalem.
the idea that you are going to get many rival power centers and harmonize them is fanciful thinking. The West is only united because its united under the force of the US Government, before that it was in a state of total war. Look at the EU as the US retreats, it is a strategic mess facing extreme difficulty coalescing upon strategic decisions.
China had to go through its civil war to achieve its unity.