That is very interesting about Tobit.
Here is the history that I have dug up, it does not inspire any confidence that the Watchtower knows what it is talking about.
Michael the Archangel is described in Daniel 10:13 as “Mi´cha·el, one of the foremost princes” and at Revelation 12:7 it says “ Mi´cha·el and his angels battled with the dragon, and the dragon and its angels battled.” In the fifty years between 1880 and 1930 there were five changes as to who Michael was.
1. An Angel that worships Jesus.
Zion’s Watch Tower 1879 November p.4 “Hence it is said, "Let all the angels of God worship him;" [that must include Michael, the chief angel , hence Michael is not the Son of God ] and the reason is, because He has "by inheritance obtained a more excellent Name than they." "
2. The Pope and Antichrist
Zion’s Watch Tower 1879 December p.6 "Michael and his angels"-- the papacy and its supporters --fought against the dragon--pagan rulers, etc.,-- and the great dragon was cast out of heaven.
3. Michael was the pre-human Jesus Christ
Zion’s Watch Tower 1883 June p.3 “Can it be that he who was called Michael--Jehovah's chief-messenger--was none other than our Lord in his pre-human condition ? … we conclude that HE must have been "chief messenger." “
4. The Pope again
The Finished Mystery 1917 p.188 “Michael.--- "Who as God," the Pope.”
5. Jesus in heaven
Since the 1930’s Michael is explained to be the heavenly name for Jesus.
Watchtower 1984 December 15 p.26 “For many years Jehovah’s Witnesses have taught that Michael is a heavenly name for the only-begotten Son of God, who was named Jesus while on earth.”