John C. Reeves provides an overview of Michael/Metatron traditions in the Sefer Zerubbabel.
John C. Reeves, Trajectories in New Eastern Apocalyptic: A Postrabbinic Jewish Apocalypse Reader (Resources for Biblical Study 45; Atlanta: Society of Biblical Literature, 2005), 184-85
References to Metatron in extant accessible versions of Sefer Zerubbabel can be catalogued as follows:
a. “Michael answered Metatron and said to me . . . “
b. “Metatron in gematria equals Shadday.”
c. “Metatron, the leader of the host of the Lord (שר צבא י"י).”
d. “to Metatron and to Michael the prince (השר).”
e. “Metatron . . . my lord Metatron (אדוני מיטטרון).”
f. “Michael who is Metatron (מיכאל והוא מי͏טטרון).”
g. “Metatron, the leader of the host of the Lord.”
h. “Metatron, the leader of the host of the Lord.”
i. “the words which Metatron spoke.”
j. “I am Metatron-Michael (מיטטרון מיכאל), the leader of the host of the Lord.”
Two things stand out in this litany of citations. First, the sole descriptive epithet borne by the angelic revealer in Sefer Zerubbabel is “the leader of the host of the Lord,” a designation modeled in turn upon the biblical description of Joshua’s startling encounter with a menacing figure at Jericho (Josh 5:13-15). No proper name is given to the mysterious entity by the biblical passage, which simply depicts him as “a man standing opposite him with a drawn sword in his hand.” Initially unrecognized and so challenged by Joshua to reveal his intentions, the strange warrior pronounces himself “the leader of the host of the Lord (שר צבא י"י), and commands the suddenly cowed Israelite leader (“Joshua fell face-down on the ground and prostrated himself”) to remove his shoes in deference to the sanctity of this site where the interview takes place. Although he remains anonymous in the biblical text, his militant posture and claim to divine honors invites comparison with the later figure of Michael, the prominent angel whom Dan 12;1 describes as “the great prince (השר הגדול) who stands over the members of your people,” and even the potential object, in one rabbinic tradition, of a heterodox sacrificial devotion. Moreover, eschatological lore roughly contemporary with the Sefer Zerubbabel cycle of traditions, and ultimately indebted to exegeses of Daniel 10-12, anticipates the reappearance of Michael in his guise as military commander for the reconquest of Eretz Israel.