In boxing you make an event because 2 guys are fighting. In MMA promoters have a fixed number of events they have to distribute their roster throughout. This requires matchmaking.
I think the confusion comes from promoter meaning different things while being the same word. In MMA the promoter owns the belt so its kind of like a sanctioning body thats running a promoting business. Like if you had the Top Rank belt instead of the WBC belt now Top Rank would need a matchmaker to move the Top Rank divisions along. Best way to explain it is those videos of Sean Shelbys or Dana Whites office where they've got the "Wall" with everybodys names under each event. Its basically a gigantic puzzle. Thats more or less what a match maker does. They make fights to move the divsion along and then spread these fights across all the different events.
He finds opponents. That's what Brad Goodman does for Top Rank, for example. But he works within the framework of TR. When I was with a TR fighter, he would find the opponents and the manager would approve them or not. In that case the manager had influence and would sometimes find the next opponent if he rejected the one TR proposed. I have a friend that is an independent matchmaker. He finds opponents for promoters that are developing fighters. For a time he was finding Mexican fighters to fight on cards in Europe and Canada. That takes a lot of weight off of the promoter. First because they may not have connections to find fighters abroad. Second, because fighters are flakes. The matchmaker, like my friend, has to make sure that the fighter has all his paperwork- visas, medicals- in order. He also serves, in a way, as a manger for fighters that have no management and lack contacts to find fights outside of their immediate vicinity. He finds them fights and takes a cut.
