The forty-second of the seventy-two is Mikael, and in the standard lists the Hebrew is written exactly as the name of the archangel Michael is written. This is not a transliteration artefact. It is the same name.
That produces a genuine oddity in the system. Michael is among the most important figures in Jewish, Christian and Islamic angelology: named in the Book of Daniel as the prince who stands for Israel, named in the Epistle of Jude and in Revelation, and assigned in the Kabbalistic scheme to a sephirah of his own, so that in the very tables the seventy-two are printed in, Michael appears twice, once as a governing archangel of an octad and once as a member of one.
The tradition does not treat them as the same being. The forty-second of the seventy-two governs five degrees of Libra and is assigned an office; the archangel governs a sephirah and a great deal else. But nothing distinguishes the names.
The likeliest explanation is straightforward and unglamorous. The derivation is mechanical: three letters at a time, from a fixed text, in a fixed order. Over seventy-two triples drawn from twenty-two consonants, some will inevitably coincide with existing names, and the suffix rule makes that more likely still, since the theophoric endings are exactly the ones that already terminate most Hebrew angelic names. A collision was close to certain, and this is one of them.
Which is a useful way to hold the whole system. Its striking features, the perfect division of the circle, the duplicate name, the appearance of a famous archangel among the seventy-two, are mostly consequences of the arithmetic, and the arithmetic is doing more of the work than the theology.