Sales is sales. Anyone with the requisite selling skills, and the aptitude to be trained about and understand their product, can be successful selling it. I have a friend with a business degree who sells airplanes. Has enough smarts to learn about the planes, but doesn’t need to actually design them to sell them. My sister is in pharmaceutical sales with a liberal arts degree. She was smart enough to be trained all about her drugs, without having any science background, and is very successful. Insurance agents can know the ins and outs of insurance without being the actuary who creates the products. As for sales engineer, It might take an engineering degree to understand the product (or get the job), but the selling skills are much more important to success.