We are so stuck on models that were developed for reasons of state that we cannot see a simple solution. Let's look past the Roman, Ottoman, Russian Empire models, as well as the nation/state models that came about in the 19th Century. Let's look back to the Holy Scriptures and to the Apostolic Church instead. What we have is the Great Commission that tells us to bring into Christ's Body all nations, as well as city-churches that were ontologically complete (Ruling bishop surrounded by his priests, deacons and laity). You go forward in time a bit and in the Apostolic Canon 34 we see the principle of how to get organized beyond the city-church level (today's equivalent being a diocese). You have a Metropolitan or senior bishop, a primate (first among equals) whose job is to make sure that unanimity of the ruling bishops is required to change anything affecting all dioceses.
Applying this concept to the Ukraine, you could have two local churches, one composed of the dioceses that want to be part of an autocephalous church and another one composed of dioceses that want to be part of the ROC (Krasnodar comes to mind). You could even have a national coordinating body composed of members of the Holy Synod of the presumably autocephalous Ukrainian Church and of the presumably autonomous Ukrainian Church-ROC. Since the basic governing principle is unanimity, it would not make a difference who chairs this coordinating body--they could take turns. Of course, this approach would not work at all if the respective churches see themselves as primarily Russians or Ukrainians, or if they become entangled with the respective states. Nonetheless, this is the only approach consistent with the Great Commission.
