How important is it for a designer's manager to be on the same product team ?

My answer to How important is it for a designer’s manager to be on the same product team?Answer by David Fradin:

I agree with Michael. It depends on and should start from a clear understanding of what your customer wants to “do.”

Historically, designers start from that point of view but don’t generally don’t go beyond that into the realm of what product managers are responsible for doing.

I write more about “do” here.

Plus what a product manager should do here.

How important is it for a designer’s manager to be on the same product team?