In OTL, the Oriental Orthodox split from the parent church when the ecumenical council decided that Christ was in "one person in two complete natures. (what? No really, that's the Wikipedia wording)" I'm no theologist, but honestly this sounds like idea that was rejected earlier of him being a human and a divine being with one body. Maybe something got lost in translation. Anyways, so those who eventually became Oriental orthodox said "Wait, that makes no sense, this is almost like what we already said was wrong. Two natures is basically separating him" Oddly they were in on and off communion with the Patriarch of Alexandria and the Bishop of Rome for another three decades. Suppose that Chalcedon happens differently, but not with the Oriental Orthodox winning. I'm imagining the council coming up with the decision "Ok, adopt ritual X, Y, and Z. As for the main debate about Christ, he is one being and whether he is of one nature human and divine or two natures, we came to the agreement that we should look into that in another date" A branch much like OTL Oriental Orthodox has a dispute, claiming the Nestorians must have gotten some influence over the council since it's so obvious Jesus Christ can't be of two natures, since that is tantamount to claiming him to be two entities in the same body. Most of the church goes much like OTL Chalcedon Christianity (precursor to the Modern Catholic Church) despite not having desolved the theological debate. Despite being a POD in 450s, can history unfold very much like OTL?