Bella Hadid and Lola Tung have equally enviable Coach bag collections, but different tastes in the New York-based brand's best-selling styles. While Hadid rotates between the Brooklyn and Chelsea carry-alls, Tung is a longtime Coachtopia loyalist. This fall, though, their Coach-filled closets finally collided: Hadid and Tung showcased the same Coachtopia Alter/Ego Bag within weeks of each other.

It all started on September 14, when Hadid wore the plaid shirt trend with a brown suede jacket, cuffed jeans , and Ugg's Classic Micro Boots . To complete her perfect-for-fall outfit, she carried—and sold out—the $295 slouchy shoulder bag, courtesy of Coach's sustainable line.…