Were focus groups polled by scientists, with the majority
deciding which way clock hands should move? Or did a great
emperor decree the direction into Roman law right after he
chose the days of the week?

The answer is actually much simpler than that. Before the
arrival of clocks, time was kept by observing a sundial. In
the Northern Hemisphere, shadows move around the sundial in
the direction now known as clockwise. Clock hands were
designed to imitate the natural movements of the sun. The
possibility exists that if clocks had originated in the
Southern Hemisphere, "clockwise" would run the other way.