Hermeneutics is the name of the discipline. Schleiermacher is the start of the trail.
I understand. You’re saying that “the” Matthew wrote an account in Hebrew and then another Matthew used to write the gospel in Greek. Could be...but it violates Occam’s Razor, “non entia multiplicandia sunt prater necessetatum”. Don’t multiply entities beyond necessity. What’s the necessity of the Hebrew source is my question?