Ideally a product manager solves or assists with many of those problems-<p>1. Reduce the ambiguity of what features to work on and what are the priorities. This involves being the barrier from other manager and team members trying to pull a fast on and changing what should be worked on.
2. Stay on top of what the latest estimates are in an honest and transparent way. Product managers as project managers should be able to translate what a particular developer says into what estimation might be in reality. They can acquire or release resources, or even change scope accordingly or at least make the case.
3. Product managers should provide developers a constant opportunity to break down tasks into components that can be tracked easily in Asana or another task management tool. This takes discipline as a product manager to enforce a system onto developers in ways that make sense.<p>Disclaimer: Product manager here.