Why does no one ever suggest the obvious? Just splitting Prussia off from Germany. Not Prussia Brandenburg or all the little bits they gobbled along the way, just Prussia proper, the bit on the Baltic on top of Poland. And then arrest most of the Prussian elite and deport the rest, while lumping the remainder into Prussia. Then bump Austria into Germany, which is still united save for Prussia, and only place part of the reparations onto new Germany and the rest on Rump Prussia.