“Game Change” helmer Jay Roach is following his longtime agent Dan Aloni from CAA to WME.Roach was one of several clients in play after Aloni parted ways with CAA two weeks ago. “Game Change,” which follows the rise of Sarah Palin, was the highest-rated HBO telepic the pay cabler has had in eight years. Roach previously directed “Recount” for HBO. Roach recently wrapped production on the Will Ferrell-Zach Galifianakis political comedy “The Campaign,” which Warner Bros. opens Aug. 10. Roach remains repped by Mosaic.