Running a man-up offense in lacrosse with a midfield triangle rotating together while the attack triangle rotates together provides several key benefits:
Keeping both triangles rotating forces the defense to constantly adjust, making it difficult for them to settle into a comfortable zone or lock onto matchups.
Defenders must track not just one player moving, but three coordinated players rotating together, increasing the likelihood of missed slides and open passing lanes.
Both triangles maintain shape rather than players randomly cutting and creating unstructured chaos.