Many Protestants also believe in the Real Presence, but it has nothing to do with a change in the bread and wine into the Body and Blood of Christ. So it would not be correct to say that Orthodox believe MERELY in the Real Presence. Their belief about what occurs during the Eucharistic celebration is more than that, wouldn’t you say?
I seriously doubt that any Orthodox persron would accept consubstantiation since that belief is contrary to the words of consecration in the Orthodox epiclesis.
There is one other theory of which I am aware that Orthodox hold. The theory applies the doctrine of the Incarnation to the change of the species - as Christ was fully human and fully divine, so are the species truly bread and wine while fully divine. I respect that viewpoint if they hold it (I’m not sure if any Orthodox CHURCHES officially hold to that view, but I have heard it from individual EO apologists). The HUUUUUGE problem with it is that the explanation does not match the words of the epiclesis. In the Incarnation, the humanity was never CHANGED or TRANSFORMED into divinity. The humanity remained fully with no comingling or confusion with the divinity. However, the words of the epiclesis indicate something that is completely different from the reality of the Incarnation. In the epiclesis, we ask the Holy Spirit to actually CHANGE or TRANSFORM or MAKE the bread and wine TO BE the Body and Blood of Christ. Two completely different “processes” exist in the teaching on the Incarnation, on the one hand, and the belief in the transformation during the Eucharist, on the other.
There are indeed Fathers in the early Church who make use of the doctrine of the Incarnation in explaining the transformation of the bread in wine, but I don’t recall them ever correlating the Incarnation per se to the change in the species. Rather their focus was the purpose of the Incarnation which was to divinize humanity, just as the Eucharist divinizes us.
Blessings,
Marduk