Peltz used to be known as a corporate raider with whom boards and CEOs usually did not get along. But he's evolved over the years and is more open to working with companies. Prime example is Heinz, which recently got sold to Warren Buffett's Berkshire Hathaway and Brazil's 3G Capital. He and Heinz CEO Bill Johnson were mortal enemies during their proxy fight in 2006, but Peltz came to be seen as a helpful Heinz board member and he now praises Johnson. Like Icahn, Peltz hasn't let his age slow him down (he's 72) and can tell you in detail about how Wendy's, a Trian investment, makes its burgers. But his son-in-law Ed Garden, who is chief investment officer, has played an increasingly bigger role. Trian president Peter May is also active, with board seats at Tiffany and Wendy's.