Doesn't the system automatically match the first two players in the queue?
So the queue will always be empty or 1 player waiting...
If not, in my opinion it doesn't matter how it matches, when I want to play, any opponent is fine. Actually, I like to play different players with various kind of decks to experience different kinds of battle instead of one single opponent who keeps on using the same deck again and again.
So I think random matching from available players is good.