Every NFL team has an identity - yes, even the Browns! Some teams are defensive-minded, and rely on that side of the ball to keep them in games, and create turnovers and big plays to flip field position. Others teams rely on their offense to lead the charge. Some are pass oriented, some are ground-and-pound. Some are a nice mix of both. There are even some that rely on the big play to make their offense potent.
The obvious mix for success would be to have a team who is competent on both sides of the ball (and special teams).