Can you provide sources for the former? It used to be thought that Aramaic arose relatively later and thus took over as the lingua franca. This then was used to date portions of the OT based on “Aramaisms.” But then we came across (centuries) earlier documents in Aramaic. The latest consensus I’m aware of (from my PhD days in 1999-2005, especially under Septuagint scholar Peter Gentry) is that Aramaic is more of a sister/cousin of Hebrew. Then again, Hebrew itself has evolved as all languages do (with Arabic as a relative exception, though there’s some development there too). I doubt Moses and Jeremiah could’ve had a conversation. Llike us and Chaucer (let alone the days of Beowulf). Even the Greek of the Septuagint (Iattic, though it’s more complicated than that) is different from the NT (Koine).
I’m not an expert on this, though I can read Biblical Hebrew, Aramaic, and Greek. Does your question bear on the notion of some that Matthew was originally written in Aramaic? Or of what languages Jesus knew and used? Is there any bearing to Peaceful Science?