Whats the point of matchmaking? I mean obviously english players can't communicate russian players.

I have m0 twins right now and I am thinking of saving crystals for m1 twins. But I cant decide between twins and thunder. Its quite fun to play with both of them, especially with supplies on. Can you give me few good reasons on why I should choose twins over thunder? And, can you give me some tips on how to use twins to the fullest?