Premades in general I don't consider disruptive, and I say that as someone who mostly solo queues. While they give an advantage to the team they are on, they are not so overwhelming that they can't be overcome. The team composition problems aren't really a function of premades, they are a function of composition balances in general. As such, the best way to deal with them is limit compositions in general. In the same way that CC limits jobs, Frontline should impose a limit of no more than two identical jobs per Full Party. This would require them to remove the ability to switch your classes once you enter the Frontline. I believe this would also incentivize people to play healers and tanks because it would be the only way to guarantee their presence on your team. In case anyone thinks this will result in entire tank and healer teams, consider that tanks and healers are incentivized to join pve instances but it's mostly dps in queue. I should also add in case it was not clear that a premade trying to queue as 1DRK+3AST would be rejected and could not queue with that comp. They could also add an 8v8v8 queue without comp restrictions that is only for premades.

Essentially, a good premade in a team that is at least somewhat competent will make everything that team does better but, if the rest of the team isn't doing what they need to do a premade can't save them. A premade is a force multiplier, it's not a magic wand.