That's why there's a whole profession called "Marketing Engineer" and another called "Sales Engineer" both of whom earn a lot more than the normal marketing and sales people.
both of whom earn a lot more than the normal marketing and sales people Not true. Good sales people earn a lot of money. In a lot of companies sales folks earn more than the management team.
If we were going to make a comparison, we would have to use expected or median pay. People in sales tend to have large variance on their paychecks.