Enter the Yorns, who, prior to joining AMG, were two of the most promising managers in town, having corralled such rising stars as Leonardo DiCaprio, Cameron Diaz, and Samuel L. Jackson while working at a smaller management firm, Addis-Wechsler, now part of IPC (This being a Michael Ovitz Situation, their decision to bolt for AMG two years ago did not transpire without the requisite amount of ranc