That's not really what the discussion is about. Not adjusting for arranged teams is indeed a big problem in Coh2 matchmaking. But the point that Rosbone and others were trying to make - agree with it or don't - is that once you lose too much ELO, it is hard to regain it. This must be true for matches with all randoms as well, not just for arranged teams.
I'd doubt that another lobby will hugely benefit CoH3, as it would just split the player base further. They need to optimize their matchmaking though.
I think everyone understands that it will take some placement matches in the beginning, which is what every ELO system does to estimate your skill. Losing a game or two more than usual should not matter for the benefit of the system. If someone quits the game because he lost 6-7 out of 10 placement games, he wouldn't be around for long anyway.
The other option is also already existing: Custom matches. There just needs to be a proper and easy way to estimate the skill of each player in the lobby as well, and then you can kick people who are too good and want to stomp new players.
Yes it is hard to recover from ELO Hell I experienced it myself and this is why I think we need a specific lobby for non ranking game with strict rules against smurfs.
Many people don't care at all about ranking, they just want to play a fair game and have fun and for those people there is absolutly no reason to force them to continuously be stuck in the ELO HELL.
Then ELO HELL will always exist, there is always a bottom side for everything where toxic low level competitive players are living but at least it only affect competitive players.
A non-ranking lobby will be beneficial for all of us. A safe place for newbe to train on competitive maps so when they decide to hit the competitive lobby button they'll already be superior to toxic competitve players making the ELO HELL even further away to anyone. And if the new player feels he's in it, he can always go back to the safe lobby to train more.
At the end the idea is that people in the ELO HELL are there by choice not because they're new. But it requires strong enforcement rules to protect the safe-lobby from toxicity.
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Custom games are dedicated to stomp, stomp IA or stomp lower level players. Even if you create a game you'll only have stomp players to join your game and leave if they understand that's not a stomp game or that they are the one who's going to be stomped.