If you want to consider the heretics in the Early Church as Christians, then, I agree not all the Early “Christians” were literalists. If you don’t consider the heretics are Christians, then what you say is NOT true!
Just to show you what the orthodox belief was, read from the Apostolic fathers, such as Ignatius of Antioch:
“Take note of those who hold heterodox opinions on the grace of Jesus Christ which has come to us, and see how contrary their opinions are to the mind of God. . . . They abstain from the Eucharist and from prayer because they do not confess that the Eucharist is the flesh of our Savior Jesus Christ, flesh which suffered for our sins and which that Father, in his goodness, raised up again. They who deny the gift of God are perishing in their disputes” (Letter to the Smyrnaeans 6:2–7:1 [A.D. 110]).
Ignatius, had been a disciple of Paul and John themselves, thus he received this teaching from the very mouth of these apostles. He was kept in very high ESTEEM in the early Church by all the Churches. That just SHOWS you what the ORTHODOX belief was as HE himself tells you what the HETERODOX heretic belief was!
I WOULD LIKE to see ONE EARLY CHURCH FATHER, who was not excommunicated (some ECFs were excommunicated such as Tertullian and Origen), who was not a “literalist” on the Eucharist as you call it.
Also, please do not cite any ECF calling the Eucharist bread and wine, as we Catholics TODAY still call the Eucharist as such and that does not mean we consider it simply bread and wine.
You would have to cite something similar to what Ignatius said but saying the contrary, such as: “Those who believe that the Eucharist is literally the body and blood of Christ are heretics” or something of the sort.