George Howard’s argument is that Shem Tob is a medieval version of Matthew that reflects a much earlier version of Matthew in Hebrew, not that it itself is the exact form of the original Hebrew Matthew. And yes, this version possibly did differ from the Greek version in significant ways. Another thing is that Shem Tob might have quoted the version inaccurately at points, which might explain odd features such as the etcetera comment. So it can be difficult to work out firstly where Shem Tob is quoting accurately and secondly where the medieval Hebrew Matthew accurately reflects a possible ancient original. Where Shem Tob wrote “the Name” in abbreviated from, the name YHWH presumably appeared in the original Hebrew version of Matthew of the first century.
One of the most interesting differences, in my opinion, is the omission of the threefold baptismal commission “in the name of the Father, the Son, and the Holy Spirit” in Matt 28.20. Was this phrase added to Matthew in later centuries to give it a more Trinitarian flavour? If I recall correctly, there are no manuscripts or quotations of this verse in that form earlier than around 250 CE and a couple of quotations which appear to omit it.
