It's not about correspondence in detail, but about correspondence in spirit. If you can find a mechanic of religious toleration that fits with the Medieval spirit, you go right ahead. Some models might be in Sicily, Moorish Spain, some Balkan states, and a few others. But the litmus test is if it fits, if it seems plausible, with Medieval Europe.
Or Western Europe between 500 AD and 700 AD. It took some time for the church to really impose itself.
