This wouldn’t work. People in plat are just as biased as those in gold and would just want whatever counters them nerfed.
There is also the boosting and win trading that happens.
I know I’ve been asked to throw for gold a good while back, which of course I didn’t accept. I play the game to have fun, losing isn’t fun.
But yea.
There isn’t any reason to trust any players on balance. What they should do is, they should look at match data in plat and up, Maybe even as low as gold 2, and see what the class representation is. Also they can look at AT data.
Then depending on what they find they can buff and nerf accordingly. They get backlogs of all kinds of data that they could use.
Such as they could see the amount of renegades were in the last MAT and figure out a safe way to bring that spec down while not ruining herald. Or they could see lack of representation of other specs and buff accordingly. Ect ect. Of course they cannot only use data and would probably have to watch gameplay to see some of the issues