Thanks guys!
I also think the original Pm lampost is out of scale, not as much in height as in width. As someone said, it is TOO fat.
Also agreed that mine is the sort of light feature you might find in a promenade more than in a street or a plaza and as it is more "baroque" and it is supposed to be more "monumental" doesn't seem so huge.
The base of the original lampost is determined by the size of the AA battery but the "neck" could be slimmer and the lantern could be smaller without loosing proportion.

I don't think there is another technical reason for the size, beyond the AA battery.