The Dallas Cowboys have a very tight group as far as their team is concerned, something that you a hope will translate into on-the-field success. Football is family. and given how much time players, coaches, staffers, etc. etc. spend together it stands to reason that they develop and share close bonds. But football is also a fleeting thing. and the make up of a team on a year-to-year basis changes dramatically.
Players are cut, some leave in free agency or are traded away. Coaches are dismissed or find opportunities elsewhere that they prefer. Things are never quite the same that they were at any point in the past which is what makes everything about an individual season and team so precious.