In DE, the map has interesting capturable items, such as Shrines, Cultural Artifacts, Pirate Docks, and Farmsteads. One can also build your Storehouses and Granaries in neutral territory, for what I call the "Strong Core/Weak Countryside" dynamic. I've slowly started adding things kinds of things to the base game's skirmish maps, but no one plays skirmish maps on the lobby, unfortunately.
Yeah, base game's siege engines are kinda weird. Too much attack range, massive vision range, huuuuge Crush damage (like artillery shells).