Poker Cooperation in online poker games

Hi, I have a dilemma and I cannot figure this out myself. Is it possible to cooperate perfectly in a game of poker and [almost] always win?

Let me describe the context a little bit: imagine a table of 6 players where five of them play against the one. The one cannot see the cards that others hold, but the 5 can see all of their cards and can cooperate as much as they want.

Now, my intuition somehow says that the cooperating group has to have some kind of advantage against the one, since they share information which is hidden from the one. The problem is that I cannot prove it mathematically and I am turning to you fellow gamblers to help me with some insight.

Your thoughts are much appreciated, thanks!