While the Early church Fathers may have been brilliant theologians, none of their writings even approach the level of inspiration of scripture. I will rely upon the scripture itself and if the scripture mentions the Nation of Israel in prophecy, then I am not going to assume that what that means is the Catholic Church or the Nation of Gentiles. And When Jesus says that these things will come to pass when the times of the Gentiles are complete, then I would assume that Jesus was not talking allegorically, but Literally.
If we take the Bible at its word, one cannot help but be a dispensationalist. If we have to allegorize according to our own understanding of history to twist the Book of Revlation into a history book rather than a book of Future events, then we are not trusting God at his word.
So if the Early Church Fathers weren't dispensationalists, that doesn't bother me a bit. They were all just confused by the Destruction of Israel in 70AD.