You have confirmed that the writer is attempting to show not merely consequential relationships between these things but consistency, which ultimately means he is attempting to justify it as a system of truth.
I believe Rome tends to make mountains out of NOTHING. I think giving them credit for "mole hills" gives too much credence to vain philosophical rationalizations and unsubstantiated traditions.
However, I think we are pretty much of the same mind here and that is good for a change.
I declare to you, brothers, that flesh and blood cannot inherit the kingdom of God, nor does the perishable inherit the imperishable. The scripture is clear.... your speculation is not rock solid.
Ignatius, Justin Martyr and other church fathers read what John wrote about this.
They spoke the same language and lived in the same era. Like John, they were part of "the east."
They understood the words of Jesus to mean His actual body and blood.
In fact, I am not aware of a single writing prior to the reformation that maintains the bread and wine are symbolic.
Perhaps you need to look harder. The problem with many of these works is that they were translated and much of their meaning was lost in translation. Secondly, many of their writings on this topic are ambiguous. You say they mean "actual body and blood," whereas they probably didn't. They wrote very ambiguously. That combined with translations makes it hard to affirm that they believed the same way that the RCC does today.
I take the Bible as my standard not the ECF. And that is the most important fact to go by.
It amazes me that some people place the ECF nearly on the level with scripture, or in some cases exactly on the level with scripture. I don't care when they lived or who they were taught by, they were still fallible human beings and their writings are fallible and subject to error and copyist error.
Seconly, you make a great point about ambiguity in their language. Many people make the same mistakes when reading old theologians like John Gill or Matthew Henry. They used a lot of careless language at times because there wasn't an issue with something they needed to clarify. Think about it, if there wasn't an issue with the mode of baptism, how clear would you be with it? What about the nature of the bread and wine? Theologians are much more careful in writing to be absolutely clear so that there can be no misunderstanding when an issue has arisen than when it hasn't.