When I say specific adjustments, I mean adjustments to the map rotation, so removals or additions. Which maps constitute the 95%? I'd say the reimplementation of Conquest has something to do with a lowered interest in battle as well though. Also, your definition of prime time is off by a few hours.
Agree with the conquest part. However I don't think I'm the only one who rarely plays EU1 nowadays because of the map rotation.
Adjustments:
1) Any map where there are almost unreachable roofs should be deleted. Do I really need to name these? I'm sure you know them as well as I do.
2) Any map where cavalry can't play at all should be deleted.
3) Any map that isn't mostly open ground should be moved to EU2. Including all city and and town maps. Some villages work fine for battle though.
4) Any with big hills should be removed or flattened as the engine is horrible for those kinds of fight.
Can't really say what to add though as I can't remember what kind of maps we used to have. However anything with open spaces would work. That open field map with a finnish name that I can't remember with couple of ruined buildings in the middle is one of my favorites. Small hills and trees give enough cover as well as those buildings.
TBF, I prolly remember the bad maps for much longer than the good maps, but come on there are some totally horrific maps in there that I can't understand even got in to the rotation. Maps like that strange maya pyramid thing. Reeeeally? Or that one city where the other team spawns outside and the only way to move is ladders and stairs.