Matchmaking Question

Are duos and trios getting matched together? Just got mowed down twice in a row with my buddy on locked gate by what appeared to be trios both times.

We're both ass at PvP, so whatever. I get that trios are KoS, but duos tend to be a little more "let's feel this out", especially on that map. This was straight slaughter and in both instances there appeared to be 3 people. It was early enough in round both times that I find it hard to believe they had already teamed up with another duo and I just didnt see the 4th guy.

What gives?