I don't know anything about architecture or power usage of these CPUs, but it wouldn't even surprise me if that 200MHz CPU took less power than that 12 MHz one.

There also is a window of almost 9 years between the launch dates of these systems (January 2006 vs December 2014)

That's six times the 18 months of Moore's law, or a factor of 64, so it could explain much of the difference.