There are a lot of points raised in this one Steve!

A good manager should listen as well as speak in both directions in their chain of command. Typically they listen to their managers and speak to their workforce: there's less listening to the workforce and passing that on up the chain because that's not the perceived hierarchy. The workforce works 'for' their manager who passes commands 'down' to their workforce. If the chain can be seen as a two-way channel, with the manager working for their workforce as well as vice versa, then efficiency, motivation and therefore productivity all benefit.

As for 'early/late': this is just one dimension in the management triangle along with "under or over budget" and "inside or outside spec/QA". With estimates being as inaccurate as we know they are, the triangle needs to adapt to cope with the limitations placed upon it by adjusting timescale, cost or deliverables.