I had the most random mixed bag match of a game ever. I join in and it was, I kid you not, one silver, one bronze, three gold, and one plat; vs five gold and one plat. The best part is, we won. Not even close. Just steam rolled them. Oh and the two healers were a silver Ana and a bronze Brig. WTF??? How did that work?
Obviously the matchmaking system maybe a bit flawed.