I rather would see the balance problem addressed with two different stages of pubs.
In the first stage (Lead?) it would include max 5 (or 7 as suggested) servers and also “Free for all” servers which would basically work just like they currently work.
In the second stage (Iron?) it would include maybe the same requirements as for comp matches (currently level 7) but you could play also 5-8vs5-8 AND there would be regulations for these servers like possible friendly fire rules, leaving punishments etc.
Reason for this is that it’s not level issue when it comes to players acting like “it’s only casuals/pubs” or not giving flying duck about teamwork or leaving the match early since it doesn’t suit them.
Proving grounds wouldn’t solve the issue that still bugs also the 7+ level folks and no amount of “education” will make them learn. But at least they can choose after that whether to join “Free for all” casuals or more regulated second stage servers.
That way we could get some quality matches out from those pubs too in the second stage.
If you want to just blast away and chip in you could join first stage and have your fun.
If you want to play more for the team and actually stay in the game you pick second stage.
I rather would make larger tutorial with simple moving bots and actual objectives etc. (which might actually help also to test different weapons and such) than shut just people down to learn stuff they might not learn anyway AND still keep the pubs like they are now.
It doesn’t help to teach new players to do their jobs in “proving grounds” if people in higher levels are thinking that “pubs don’t matter, it’s just fun” or “pubs cannot be balanced since it’s just casual” or “level’s don’t matter but you must first have level x before you can considered not noob”.
AND NO, second stage isn’t same as competitive since it has also servers for more than 5vs5 and it doesn’t have ranking system. Also I think you could fit that party/team system there without ruining “free for all” servers. Like few members of premade teams + randoms on both sides.
But I can see I will probably will play this game just casually now and then so it’s probably not my business anymore. Just my two cents not worth of penny.