No, I don't get it. You make unwarranted assumptions by looking at the NT writers and comparing them for all the wrong reasons.The fact is when you compare the OT quotes in Matthew with the Other NT writers what we find is that the other writers coincide with LXX translations of the OT. Thus showing Matthew quotes of the OT are an independent translation of what the apostles were using. The question then is why is this. Either 1) Matthew wrote the gospel to the JEWS and HEBREWS in their second language Greek and translated OT scripture without using a source text. 2) Matthew wrote the gospel in Aramaic and his disciples compiled the work together for their Greek Audiences and translated directely from the Aramaic use rather than old hebrew into Greek from the OT not using source LXX. Get it?
First of all the LXX has nothing to do with it.
Secondly the NT writers were inspired by God, not the LXX.
Thirdly each NT writer had a different purpose and a different audience which affected their style of writing and their vocabulary.
Matthew wrote to primarily a Jewish audience demonstrating that Christ was indeed the Messiah. He uses more references to the OT than any other gospel writer.
Mark wrote to primarily to a Roman audience demonstrating that Christ was a Servant. Notice there is no genealogy. No one cares about the genealogy of a servant. He came not to be ministered unto but to minister and to give his life a ransom for many.
Luke wrote primarily to a Greek audience demonstrating that Christ was the son of man. Luke was a physician. He wrote specifically to Theophilus, a Greek friend. His gospel was volume one and the book of Acts was volume two. In the gospel the humanity of Christ is emphasized.
John wrote primarily to the world at large demonstrating that Christ was deity. It was written well after the others and gives additional information that the others don't have. If any Gospel uses Hebraic and Aramaic expressions it is John, who, when he uses them, stops and translates them for us.
Matthew is different, because he had a different purpose, a different audience, not because it was translated from Aramaic. Your assumptions are hogwash, unsubstantiated, based on fiction, and an argument from silence.