It seems to me that in my FP games the Dark Servants are overrun with dragons, but in my DS games they seem very hard to find, despite looking in the usual place.
It does seem that they have different stomping grounds in the various seasons.
So I wonder – are there players out there with secret knowledge of where the dragons go in the Summer etc.? I might start going through all my past turns to track which dragons I have encountered where and in which season. Though I suspect there are hexes where some go in certain seasons, which are unknown to most of us.