collaboration across these agencies based on client needs and opportunities. solutions could be led by Leo Burnett , others by SMG , others by Digitas. aggregation of some of the most powerful tools and talent in the industry. full-service arrangement or select custom-built solution teams. continents , the Groupe employs approximately 44,000 professionals. foremost on human behaviour before attempting to tell a brand 's story. the world 's top five creatively awarded networks worldwide .