‘Magi’ would not have been a general word for ‘magician’ when the New Testament was written. The word ‘Magi’ originally referred to priests of Persian Zoroaster.
The earliest references to the word 'magi' refer to a priestly class, not a generic word for great. The idea of the magi as 'kings' actually come from the Latin word 'mega', which means Great.
Tell us which language the story of the three Magi is written. If it was written in Latin, then I will admit that the most probable translation is 'great' or 'kingly'. If the language was Hebrew or Greek, then I will suggest that Magi really means priest.
You are suggesting that the cognate of Magi is ‘mega’, which means ‘great’, ‘splendid’ or ‘noble’. It was a word associated with noblemen and secular power. Noblemen have a large retinue of attendants. The three Magi in the story don’t have a retinue of attendants.
Although this is possible, I don’t think this quite matches the context of the New Testament story. The Magi in this story are following a Star, not leading an Army.They are reading the Stars, something I don’t think noblemen in that time did personally. Their incense seem appropriate sacrifices to a Hebrew Temple. So they seem to resemble priests rather than kings.
https://en.wikipedia.org/wiki/Magi
‘Magi (/ˈmeɪdʒaɪ/; Latin plural of magus; Ancient*Greek: μάγος magos; Kurdish:mager,Old Persian: 𐎶𐎦𐎢𐏁 maguš, Persian: مُغ mogh; English singular magian, mage, magus, magusian, magusaean; , Turkish: mecî) is a term, used since at least the 6th century BCE, to denote followers of Zoroastrianism or Zoroaster. The earliest known usage of the word Magi is in the trilingual inscription written by Darius the Great, known as the Behistun Inscription. Old Persian texts, pre-dating the Hellenistic period, refer to a Magus as a Zurvanic, and presumably Zoroastrian, priest.
Pervasive throughout the Eastern Mediterranean and Western Asia until late antiquity and beyond, mágos, "Magian" or "magician," was influenced by (and eventually displaced) Greek goēs (γόης), the older word for a practitioner of magic, to include astrology, alchemy and other forms of esoteric knowledge. This association was in turn the product of the Hellenistic fascination for (Pseudo‑)Zoroaster, who was perceived by the Greeks to be the "Chaldean", "founder" of the Magi and "inventor" of both astrology and magic, a meaning that still survives in the modern-day words "magic" and "magician".
In English, the term "magi" is most commonly used in reference to the "μάγοι" from the east who visit Jesus in Chapter 2 of the Gospel of Matthew Matthew 2:1, and are now often translated as "wise men" in English versions.[1] The plural "magi" entered the English language from Latin around 1200, in reference to these. The singular appears considerably later, in the late 14th century, when it was borrowed from Old French in the meaning magician together with magic.
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The Avestan word 'magâunô', i.e. the religious caste of the Medes, (see Yasna 33.7:' ýâ sruyê parê magâunô ' = 'so I can be heard beyond Magi'), seems to be the origin of the term.’
The meaning of the prefix ‘magni’ was very likely derived from ‘magi’.
The word ‘magnificent’ originated in Old French which took it from the Latin in the fourteenth century.
http://www.etymonline.com/index.php?term=magnificent
magnificent (adj.)
mid-15c., from Old French magnificent, a back-formation from Latin magnificentior, comparative of magnificus "great, elevated, noble, distinguished," literally "doing great deeds" (see magnificence).
http://www.etymonline.com/index.php?term=magnificence&allowed_in_frame=0
magnificence (n.)
mid-14c., "great-mindedness, courage," from Old French magnificence "splendor, nobility, grandeur," from Latin magnificentia "splendor, munificence," from stem of magnificus "great, elevated, noble, eminent," also "splendid, rich, fine, costly," literally "doing great deeds," from magnus "great" (see magnate) + root of facere "to make" (see factitious). Meaning "greatness, grandeur, glory" in English is from late 14c. That of "beauty, splendor, wealth" is 15c. As one of the Aristotelian and scholastic virtues, it translates Greek megaloprepeia "liberality of expenditure combined with good taste."
Of course, the Magi could have been Rabbis!
The Jewish religion was not well delineated from Zorastrianism in those days. Astrology was well delineated from religion in those days. So Magi could have meant priest as the Hebrews saw them, as Rabbis!