Two men in the long history of the Dodgers managed for 20 seasons or more. Walter Alston, and Tom Lasorda. Manny Mota and Jim Gilliam had careers of more than ten years with LA and then coached for several more years. Vin Scully was the voice of the Dodgers for 67 years. Most teams do not come close to having someone save an announcer here and there around that long. Two managers with 20-year tenures? No other team has as many. And one, Wilbert Robinson, was the manager for 19 years.
The longest-tenured manager ever is Connie Mack, and I seriously doubt anyone will ever come close to matching his 53 years as a manager, with 50 of those coming as skipper of the A’s.