I don't really agree with this view point that engineering should know less then PM. In a good team, Engineering knows what features are there, why are they there and what sales / customers are hankering for, and also how they where implemented. Sales is generally aware of what is more valuable to a given customer Marketing has an overall idea of how the market is behaving. PM is the crucible where all these information comes in and they need to define how product will be built. But please note, each subteam should have a strong idea of the market. If not, then people are not effectively communicating. Lack of communication is a sure sign of dysfunctional team, which results in each teams working on their pet projects, but no one knows when what will come out of the whole process.