My first triple master was a master a Builder, Scientist, and Doctor. He picked up the first 2 quickly, and getting the doctoring mastered wasn't really all that difficult. I would drop him on one of the plants, then go through my numberpad and look for collectibles and mushrooms while he was studying it. Then i'd drop him again and make another round. I also made the "sick stew" and made everyone sick, then had him heal them all. Took 3 stews to get him to be a Master, but it worked.