Ideas to develop

Great Northern Empire
-and relation of said to Saga of Aceries

Character of ages:
Aceries takes place in Age of Heroism
Verial takes place in Age of Apogee and Beginning Decline
Vampiro takes place in Age of Darkness

Saen
-North vs South.
-If it had to be described it is something like a Carolingian system, that is, a kingdom whose RW parallel would be something of a Latin-Germanic synthesis.

Nature of international knowledge
-It seems that in these campaigns there was knowledge of international travel and trade, possibly more pronounced in later campaigns than earlier ... or perhaps reaching a peak at Verial and once again declining

What about minor characters
-The campaign of Seigneur Blaze comes to mind...  This was forgotten in the first overview - and perhaps there were others also?

Racial traits of the peoples of Arkon

What about Demihumans?  Common in earlier campaigns, seemingly fading by later.  More must be said...