I’m not saying this for all instances. Maybe I’ve been fortunate. 100% of project managers I’ve worked alongside looked for parallel paths, and that’s their job. But once the feedback from tech SME is that these are linear dependencies, they said okay. Let’s move to discuss how to communicate this to leadership and customer.
My personal experience. Your mileage obviously may vary greatly. But a PM that doesn’t understand the mythical man month, isn’t much of a PM. Or even a competent team member.