It is not inconsistent in the least once you dig deep into the Scripture.
Let's take one example. Christ says "My body is true food and my blood true drink." He expounds on that metaphor with complete literalness, to the extent that people walk away from His discourse. "This saying is hard...who can listen to it?" Did anything similar happen when he said "I am the door"? "I am the way?" No it didn't.
The closest Our Lord came to saying what he said with the Eucharist was when He said "I am the true vine". HOWEVER...note that the Greek word used for "true" there differs slightly. My flesh is true (alethes) food, but I am the true (alethinos) vine. There is an important distinction in those two related Greek words. Alethes means "true, real, genuine"...true as a matter of fact, true in substance. Alethinos means "true by analogy". So Our Lord's flesh was true food in fact, while He was the true vine by analogy. Don't forget, most of these writers marshmallow quoted were reading the New Testament in Greek. They would have seen that difference straight away.
Bauer, Arndt, and Gingrich, Second Edition, pp. 36-37