Old Occupations lists a Drillman, probably similar to a drillsmith. A drillman was an agricultural worker who operated a seed drill. I wonder if a drillsmith was someone who maybe made the seed drills.
Yes, I would think that a drillsmith would have required some training and maybe experience. Have you got any idea if he had any occupations beforehand such as blacksmith or carver etc? If not then he probably started out as a drillsmith and maybe did an apprenticeship.