Agreeing with other posters here, there isn't a right way to play. If an entire group has issues with a player, it's time to have a conversation. But even then, it's not that anyone is wrong, it's just that playstyles don't necessarily mesh.
I will say, however, as someone who plays a lot of "Combat Deck Wins (sometimes)", player 3 is playing the way they need to in order to have a chance. You don't really have the luxury of bringing everyone's life totals down together. The longer you have multiple people alive, the less likely you are to be able to actually get in to a winning position in the face of removal. Or life gain. Or any of the other dozen ways to shut down aggressive decks in multiplayer.
I will say, however, as someone who plays a lot of "Combat Deck Wins (sometimes)", player 3 is playing the way they need to in order to have a chance. You don't really have the luxury of bringing everyone's life totals down together. The longer you have multiple people alive, the less likely you are to be able to actually get in to a winning position in the face of removal. Or life gain. Or any of the other dozen ways to shut down aggressive decks in multiplayer.
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