What does the sequential naming of the Harvest and Hunter's Moons illustrate about ancient sky-watching?

Answer

That the naming system prioritized environmental readiness over a fixed calendar month.

The shifting timing of the Hunter's Moon demonstrates that the naming convention was based on the sequence of events tied directly to environmental readiness, rather than being tied rigidly to specific calendar dates.

What does the sequential naming of the Harvest and Hunter's Moons illustrate about ancient sky-watching?
nameastronomyMoonfull moonHunter moon