Neither the Moravians, nor the Hussites nor Herrnhuter had Orthodox roots. That is a relatively recent revisionist idea put forward by some Orthodox - especially the Czech Orthodox Church which is deperately trying to create a history since it practically lacks one.
Jerome of Prague is often held up as if he were a convert to Eastern Orthodoxy - yet his “conversion” went unnoted by everyone in his day including by Jerome himself. Not even his enemies, such as John-Jerome of Prague, ever mentioned it.
The connection to Eastern Orthodoxy—of which you are correct, there is nothing at all direct—is that centuries before Hus, in the 9th C., Bohemia and Moravia had been evangelized by Orthodox missionaries (Sts. Cyril and Methodius) ...then subsequently when these kingdoms became part of the Germanic Holy Roman Empire, Roman Catholicism was adopted.
Personally I believe the further east you go in Europe (starting with Czech) the more amenable historic attitudes are toward the acceptance of mystery present in Eastern Orthodoxy. I once met a Bulgarian Roman Catholic—eastern rite—and he had quite different attitudes toward certain religious ideas than his western Roman Catholic brethren.
Interestingly, even Luther, and Lutheranism, is more friendly to mystery, than say Calvinism and other more western Protestant traditions. There’s something about that part of the world I guess...