Mahjong with Aliens

Do you know Mandarin? It is shifting. The voice you're about to hear belongs to the Chinese military chief... General Shang. Pull it up! We got a satellite feed here of who he's talking to, if you want to look. Wait, go back. Stop. He's saying that each of the twelve is offering advanced technology. Go back again. And play. ‘Our science team is attempting to decode the sets.’ Sets. I don't know what that means. Something about advantage, suits, honor and, uh, flowers. I don't know. That's all. I don't know what it means either. An hour ago, China mobilized forces. And now, Russia's following suit. Shang's about to start something. Following suit. Suits. Suits, honor, flowers... Colonel, those are all tile sets in mahjong. God, are they...? Are they using a game to converse with their heptapods? Maybe. Why? Well, let's say that I taught them chess instead of English. Every conversation would be a game. Every idea expressed through opposition, victory, defeat. You see the problem? If all I ever gave you was a hammer, everything's a nail.