I believe they can be. Specifically by saying that Cyril and the Miaphysites are referring to the hypostasis of Christ, and that in recognizing the distinction but not separation of the humanity and divinity of Christ they are in fact confessing the same faith but with different terminology.
Reconciling the Assyrian Church of the East is harder but Mar Dinkha IV on his accession repudiated the worst parts of it, and I admire him for it. But I believe there are hardliners, particularly in the breakaway Ancient Church of the East. But in my proposed Grand Solution, I think we can reunite with the Assyrians by rehabilitating the person, but not the horrible Christology, of Theodore of Mopsuestia, on the grounds of his great virtue, his obedience to the church in his lifetime, and his friendship with John Chrysostom. The anathema would be redirected at Diodore and Theodoret who taught him and expounded upon him respectively, and who were more responsible for leading Nestorius astray IMO. So if we throw the Assyrians the bone of Theodore no longer being anathematized in his person, but merely being declared in error on Christological matters. This should be enough I think to make them forget about Nestorius and join in with the church. I could be wrong. A engineered schism though by which those still loyal to Nestorius would be assigned to the Ancient Church of the East with reconciliation to be attempted at a later date might work.
As for the Oriental and Eastern Orthodox, I believe that the compatibility of their faith is witnessed by the similarity in worship, and the fact that both communions use icons, and indeed the Orientals have never embraced iconoclasm to the extent it was embraced in Constantinople; there was a minor outbreak IIRC in Eastern Armenia which the Catholicos quickly moved to suppress, in the sixth century. If you read the Armenian liturgy furthermore it is almost identical to the Byzantine one. The Coptic and Syriac Rites are a little different, but still recognizably of common origin. In particular the service of Holy Unction used by the Copts and the Byzantines is strikingly similiar; I believe both preserve portions of an ancient unified rite that is one of the oldest in the church, but in their present, mildly differentiated forms, are equally exquisite.
There was an outbreak of crypto Nestorianism following Chalcedon, largely in the Western Empire. The Fifth Ecumenical Council was designed to correct this, and reconcile the Oriental Orthodox, but politics made such a reconciliation impossible at that time. The post-Chalcedonian misinterpretation of Chalcedon as a license to re-embrace Nestorianism though is attested by the Three Chapters Controversy, which IMO in turn validates the concerns of the Oriental Orthodox. But there was a need to make clear after the scandal caused by Eutyches,,who villainously deceived Pope Dioscorus, the distinction but not the separation of the humanity and divinity. To separate them is to Nestoranize; to assert their distinction in unity is Orthodox. Both Orientals and Easterns confess that the two parties confess one Christ, fully human and divine, without confusion, division or separation. The Assyrians also essentially confess this; there's almost no trace of the grotesque duo hypostatic Christology in their liturgy. The only problem is they're convinced Cyril was evil and Nestorius was a confessor, and this ignores some of the evil things Nestorius did as Patriarch before going off on the whole Christotokos thing that brought him down. There is also their hesitancy to say "Theotokos" but I do believe appeal to unity due to the HORRORS, the profound and terrible evil of the wicked men of ISIL, who kill Antiochians, Syriac Orthodox, Assyrians, Chaldeans, Melkites and Syriac Catholics, and indeed Copts, without distinctions, is enough to cause them to be willing to unite in holy communion, but if we threw them a bone like rehabilitating Theodore of Mopsuestia, who was close friends with John Chrysostom, I think that would grease the wheels a bit to make it happen.
By the way, IMO the failure of Pope Leo I to prevent the Nestorian and Chalcedonian schisms is a convincing indictment of Papal Infallibility, which Deacon Lance, lamentably separates you from the Orthodox. If Leo were infallible he could have stopped these schisms; the manner in which his Tome appears to contradict Cyril, though doubtless accidental, did fuel the flames of the schism.
By the way, in an attempt to comply with the forum rules regarding discussion of Chalcedon, I have omitted referring to anyone as Saint or Mar/Mor or I believe as a heretic in this thread even in cases where I think we all agree as to their sainthood (e.g. John Chrysostom). Salpy or any other mods who read this, if I have misread the rules and failed to properly comply with the requirements regarding the veneration of saints and the avoidance of polemics in discussions of Chalcedon, I want to apologize in advance, and beg you to PM me my error so I can edit the post to make it right Id the mistake was serious enough.
I love the Eastern Orthodox, the Oriental Orthodox and the Assyrians. I also love the Catholocs and the continuing conservative Anglicans and Old Catholics, and the dogmatically orthodox Episcopi Vagantes. I wish we could all be in communion.
I have fantasizes about abducting all the patriarchs to a secret underground base on the island of Niihau in Hawaii, which I would lease from Mr. Robinson for this purpose, and replacing them with robotic duplicates, who would then convene an ecumenical council. Voice actors would converse daily with the captive patriarchs and then impersonate them by providing the voice for the robots. Then after a couple of years of luxurious island living, the abducted Patriarchs would be released back into the world and their robotic duplicates confined to the scrap heap, and being the holy men that they are, could then judge if the restoration of communion was working and if it wasn't, suppress it. I would then submit myself to them and allow them to terminate my life if they felt I deserved it. A high risk strategy. Unfortunately I'm not a James Bond villain, so I suspect we will have to work things out the old fashioned way as Christians.
Note the preceding paragraph is a joke and I would. In fact sacrifice my life to prevent anyone from committing sacrilege by laying hands on any Patriarch of an autocephalous church, even one who I disagree with like Pope Francis.