The key here is that product is a buffer between sales and engineering. Sales teams should be a constant source of feedback for product teams who can spot the synergies you're talking about.
SDMs should be a constant buffer between engineers and product.
This works wonders at an enterprise or mid market company. I don't envy smaller companies that need to drive alignment between stakeholders that have to straddle all of these lines.
A good portion of my job is helping small businesses find that alignment and being able to present the big picture to all of these teams. Somehow being external seems to help.