What typically provide the most honest, and most crucial and useful, feedback about the performance of a team?

The answer for the given question above would be EXTERNAL CUSTOMERS. It is the external customers who provide the most honest, and most crucial and useful, feedback about the performance of a team. External customers refer to those people outside the company who purchase and consume the products or services. Hope this answer helps.

They could provide internships towards graduates to allow them to acquire working experience.
They could also provide training to help graduates have an understanding of what they are expected of in the workplace.