There's also slightly more nuance to what kind of dps, healers and tanks we're talking about for matched teams. It's not necessarily so cut-and-dry that it's figured out simply by the number of red/blue/green that pop up on the player portrait loading screen. A SGE and AST don't necessarily hold the same amount of weight in every given composition or gameplan.

As it was already mentioned, I find the biggest flaw in the match-making algorithm is stuff like when there's exactly only three melee jobs in a match, one being a NIN, and the matchmaking expects the NIN to carry the weight of the "only melee" job to a team versus the other team with an actual tank plus something like a SAM or DRG. Or even the NIN versus a SAM and DRG.