The Captain of the host and Michael the Archangel are both certainly Jesus Christ. Here’s an excerpt from an article on the Captain of the host:
https://faithsaves.net/captain-host-lord-analysis-joshua-513-15/
The word “captain” (rs) is common in the OT, appearing 421 times, translated most commonly “prince” (208 times, also KJV margin here) and secondly “captain” (130 times), followed by “chief” and “ruler” (33 times each). This “man” who appears before Joshua asserts his authority when he employs this designation. Nowhere else in the Bible does the phrase “captain/prince of the hosts of the LORD” appear, but the phrase “captain(s) of the host” appears in the Pentateuch in Gen 21:22, 32, 26:26, Num 31:14, 48, and De 20:9, and indicates, when found in the singular, the supreme military authority, which, when “captain” is plural, indicates this same authority divided among a group. In Joshua 5 the Captain further emphasizes the greatness of his authority through the emphatic employment of the first person pronoun yna, which also receives an early placement in the Hebrew clause (In Heb. order, “No; but I, the captain of the host of the LORD, now I have come.”) The most comparable reference to the phrase of Joshua 5:14 appears in Daniel 8:11, where the “little horn (v. 9)…magnified himself even to the prince of the host (abuh-rs).” The “prince of the host” in Daniel 8:11 is probably God himself, the “Prince of princes” (Dan 8:25, Myrs-rs) whose worship Antiochus IV Epiphanes attempted to end. It is possible that the “now” also expresses the divinity of the Captain: “I who formerly appeared as the Jehovah of the burning bush (Ex 3), and who was announced as the tutelary Angel of the traveling hosts (Ex 23:23), now appear in the different character of the Divine Defender of the covenant nation; and as my presence formerly made Sinai holy (Ex 19:20), so now doth it sanctify the spot upon which I tread.”[5] Apart from this, the appearance of the Captain at the commencement of the conquest of Canaan constitutes a fulfillment of the promise of Ex 23:20-23[6] for guidance and victory— the Angel’s manifestation to confirm this justifies the “now” of his “am I come” (or “I have come,” a Qal perfect).
Joshua would have understood the phrase “host of the LORD” to refer to the army of Israel; in addition to the use of the very similar phrase “the hosts of the LORD” in Ex 12:41, the overwhelming majority of the appearances of the word “host” (abu) in the Pentateuch relate to the chosen nation. Furthermore, Joshua had queried the allegiance of the Man with the Canaanite or Israelite forces, so his reply naturally deals with them. Nevertheless, the Captain was also head over all the forces which Jehovah had dominion of, including the heavens and the earth (termed a “host” in Gen 2:1), the stars (De 4:19, 17:3), and the ranks of the heavenly beings (1 Ki 22:19). All of these arrayed themselves on the side of Israel; the heavens dropped hailstones upon the Canaanites (Josh 10:11), the earth fought for Israel (Hab 3:3-19, cf. Jud 5:4, Ps 68:7-8, 1 Sam 14:15), as did the stars (Jud 5:20), the sun and the moon (Josh 10:13), the heavenly hosts (De 33:2), and other creatures (Ex 23:28, De 7:20, Jos 24:12). Jehovah, the God of all the earth, had all the resources of his creation, and the direct workings of his Omnipotent hand to supplement the strength of Israel’s armies (cf. 2 Ki 6:17) and give his people victory over cities such as Jericho in supernatural ways.
You would have to be spiritually blind not to see the similarities between the two characters/titles of Christ.
And of course the one concept that you still cannot (refuse to) understand or admit to is that Angel can mean MESSENGER.
[2] The word “angel” (Kalm) has the root idea of “messenger,” and is so translated in reference to non-spirit beings in Gen 32:3, 6, Num 20:14, 21:21, and many other places in Scripture. The fact that the hwhy Kalm is called an “angel” does not automatically divorce him from the possibility of a place within the Godhead to the separate section of the modern systematic theology text entitled “Angelology.” Christ repeatedly emphasized that the Father had sent him (Jn 6:40, 8:18, 17:21, 23, etc.), was an “Apostle” or “sent one/messenger,” apostolov, Heb 3:1, and apparently was explicitly termed an aggelov yeou, an “angel of God,” in Gal 4:14.