How about make it so then players can only duo with people who are one tier ahead of them or below.

for example a Gold 5 can only duo with a silver 1, a Gold 5, or a Gold 4. So then their is none of this bullshit unbalance that I keep seeing where a team is like. A gold 5, 3 Gold 1s and then a silver 1 vs a team of all gold 5s. Like that shit is not fair nor balanced.