Is writing "Allah, Messenger, Muhammad" on the Prophet's ring - may Allah bless him and grant him peace - considered polytheism (shirk)?

The inscription on the Prophet's ring (peace and blessings be upon him) consisted of three lines: Muhammad (one line), Messenger (one line), and Allah (one line). It appears that the writing was from top to bottom (Muhammad, Messenger, Allah), not the reverse. The writing was engraved in reverse so that the seal would appear straight when printed, which is natural for seals and there is no objection to it. And if we assume the correctness of writing "Allah, Muhammad, Messenger," then the intended meaning is "Muhammad is the Messenger of Allah," and the precedence of Allah's name is out of reverence.