I've played 3 tribes to the finish now and I've only had one truly horrible worker. Total "loser" who disliked work and herbs, I couldn't even make him a doctor. The women all ran away from him, too. I did finally get him to master farmer, but it took a LOT of drops in the ocean and onto the field. My best worker was a runner who also liked lifting, talk about the perfect builder, then I switched him to farming and he had the bin overflowing!