First of all you can't really compare Mag and Busken. Combusken operates as a frail hyper offense killer and lategame sweeper that can either run physical or special which makes it quite unpredictable. Magmortar on the other hand is a special tank that can dent holes in defensive cores with the option to run mixed. And the argument that it's bad cause it has moves which are not 100 percent is also really shaky. Rotom-F, probably the best mon of last gen always ran Blizzard or Oricorio/Swanna with Hurricane. Pokemon is a RNG based game and if you hate missing, Busken isn't the right mon for you.