Matchmaking without the Trinity: how would you do it?

[Connor]

They could always do this:

Instance Server: Hey Duty Finder! I got an opening, find me some victims, I mean players.
Duty Finder: On It!
Duty Finder: Let's see, I need a tank, ooh, I see one! Snagged!
Duty Finder: I need a healer, I see three of those, picking the one who has waited the longest.
Duty Finder: Manual says I need 2 DP, jumping Jehosaphat! How do I pick just 2? Screw it, taking 2 at random, they'll never know the difference.
Duty Finder: I need a Support, whatever that is. Support? Support? Hell with it, have a DPS instead.
Duty Finder: Take them away Instance Server, I need to look up what a support job is.

It could default to 1-1-2-1, if it cannot find a support after a period of time it changes to 1-1-3 instead. Would make DPS happy since the population is about 1-1-3 anyway.

This is always how I imagined a 'support' role to work too. I think this way perfectly allows a 'support' role whilst not creating massive queues