You may be right and I may be crazy - Billy Joel.
The reason why I don’t agree that it is a question is for two reasons.
1. Michael is a real being, doing real things. He’s not written about in a commentary format in the same sort of format that the leviathan is spoken of in Job, where Job is commenting on the power of God and whatnot.
2. Michael contends directly with Satan. Satan is the reason we’re in this mess and he’s the main antagonist. It would seem a strange thing that God would pass the responsibility off to somebody lesser than Satan was. It could only be appropriate that God Himself takes care of business when dealing with him.
That's exactly what God does, the more profoundly to humiliate Satan. He's not setting out to appeal to Satan's pride, which is already well out of control. He uses the lowly to humble the great; cf Lk 1:46-55.
The following prayer was said at the end of every Catholic Mass from about 1880 until 1963:
St. Michael the Archangel, defend us in battle; be our defense against the wickedness and snares of the devil. May God rebuke him, we humbly pray, and do thou, O prince of the heavenly host, by the power of God, thrust into hell Satan, and all the evil spirits, who prowl about the world seeking the ruin and destruction of souls.