How to play royalist in JJ competition?

Royalism is an entertainment, in which five people play four decks of poker. In the game, five people are divided into two factions to compete, one is the "emperor" and the other is the "royalist" (hereinafter referred to as the "revolutionary party"). The ultimate goal is to do everything possible to play a group of cards as soon as possible and strive for a better ranking. Finally, win or lose by ranking points.

The fun of this game is that there are only two people in the "Emperor" group, and three people in the group against the "Revolutionary Party" are at a disadvantage. Therefore, "royalists" should hide in the "revolutionary party", provoke mutual suspicion of the "revolutionary party" and secretly assist the "emperor" to win his own group. In addition to the obvious enemy of the Emperor, the "Revolutionary Party" group also has a hidden enemy "Royalist Party". We should not only prevent the emperor from branching out, but also try to find out who the hidden royalists are, so we should help each other and guard against each other.