I just finished the first campaign mission (Griffin Bane) on Normal difficulty and apparently my completion score was 12250 (46%). The tooltip says I can
Increase [my] score by completing quests, picking up resources and artifacts, defeating neutral packs and heroes and controlling capturable buildings at the end of the map.
However, it's not that big a map. Far as I know, I visited every corner, completed every quest, beat every enemy and gathered all available resources.
What am I missing?