There's a job vacancy for a salesman, one of the two applicants has a high diploma in marketing and the second have a long experience in the Market, whom would you chose?

I would simply choose the experienced one because experience beats the knowledge

I would ask them a same situational problem and I'd chose whoever has the most creative and practical answer because the real knowledge cannot be defined just by what they have achieved in the past but on how they can smoothly manage a difficult situation.