Hello Graham, thanks for responding.
My friend, you have great faith!
You've just articulated a position of blind faith.
We do have directly evidence pointing to Matthew. It's an extant Scripture containing a prophecy that matches the description, and Irenaeus records Matthew as being written early enough for Paul to be aware of it when he wrote 1 Corinthians.
Yet you would rather discount this evidence in favor of the blind faith that somewhere else there might have been something else.
My friend, I don't have as much faith as you.