What is the ideal structure for product managers and product designers?

What about scenarios when you can't have the ideal like when there are too few product managers or product designers?

How should product managers and product designers combine forces?

How can product designers better collaborate with product managers?

How can product managers better collaborate with product designers? 

What are some keys to success?

Shoutouts:

• The User Experience Team of One (book)
• Ermal Fraze, inventor of pop-top soda can