Depends on the pike. They are very variable, even within the species. Some pikes are more aggressive than snakeheads, eating and territorial. Its normally really not that bad though. I've kept pikes in MANY community tanks with little to no trouble.
People have just given them a bad rep that they don't really deserve. Honestly they are no more aggressive than most of your CA/SA cichlids. Many of them are also more attractive to boot. Very unique, interesting, 'interactive' fish!!
Marvin, awesome xingu I female man! Love those pictures!