(1 Bodily-kinesthetic, 2 Interpersonal, 3 Verbal-linguistic, 4 Logical-mathematical, 5 Intrapersonal, 6 Visual-spatial, 7 Musical, 8 Naturalistic). This makes perfect sense—people are good at different things.
The reality is that all your employees or vendors are better at some things than others. A lot of your personal success comes from recognizing what people are good at and letting them do it. The problem of course is that your myopic because you have a relationship, be it with a vendor or employee based on them performing a specific function. Before you discard them entirely perhaps it would be beneficial to give them other duties.