Someone by nature a skilled trader, and someone will never be able to master it? Where is it better to get such knowledge: in special schools or courses or on personal experience working in a commercial company?
We cannot always count on talent. Learning is a necessity for both the talented & the untalented. The talented will get more knowledge of improving skills in a scientific way & this improvement will involve important aspects such as precision, statistics, optimization, shaping up realistic predictions, market trends...etc.
It should be not person ability but persons interest and inclination to become good sales person, training and teaching will enhance the professionalism. The training will sharpen the skills.