Fun Fact: The 12 Tribes as illustrated by the Choshen Mishpat, the breastplate of the High Priest / Kohen Gadol, and the 12 Tribes as illustrated in the encampment differ. Why? Because the Choshen Mishpat has them in order of birth, and the Tribal Encampment below AND the astrological array above has them in the Kabbalistic order (which is Levi separated from the 12, and Joseph's portion given over to Ephraim & Menashe). This is implied in the Sefer Yetzirah as well as explicitly mentioned in the earliest Midrashic references to the associations between the Tribes and Constellations and is the order of the Arizal.
What is the significance of this difference? The Tribes in their birth order are fixed upon the heart of the High Priest, and therefore symbolically upon the heart of G*d. They don't change or move. This represents the eternal and unchanging bond of love between Am Yisrael and HKBH.
The Tribes in their encampment order are dynamic; they make camp 42 times over the 40 year sojourn through the desert, ALWAYS in the same array, with Yehuda to the east, Ephraim to the west, Dan to the north, Reuven to the south, etc. "As above, so below", the constellations above mirrored the encampment below. During those years in the desert, the former slaves grew up, grew old, died off, more were born, and a number of significant events occurred detailed in the Torah, including the rebellion of Korach. The Kabbalistic order is dynamic as well, facilitating development, maturity, and relationship. It's where and how we live as Children of Israel, throughout time and history.