Their matchmaking is resemblant of a tournament at times. There are often #1 vs #2 contender fights. Scheduling works out a lot better when you have big deep divisions and allows for you to account for other variables, such as dominance of performances or demand relevant. It was really when UFC was struggling with talent that their matchmaking of champions often was lacking the linear logic of tournament determined champions and contenders (see Arlovski vs Buentello or Franklin vs Quarry type stuff). You get the occasional Bisping vs Henderson for the buys and the timing of Henderson's historic career coming to a close, RDA vs McGregor for the storyline and buys, Mighty Mouse fighting guys just cause there's no one to fight... but it's mostly real deal top talent fighting relevant top talent.