CoE is a sandbox MMORPG Think of albion, and eve, with even more sandbox elements, that even go into detail about letting players create the rules that people follow in their kingdoms, duchy, county, and Capital. IF you want a building a player or NPC has to build it.
AoC is a themepark game with some sandbox elements Think of it as a meld of GW2 and Archage.
They are completely different genres, that cater to different user experiences. And such different players, CoE is more of a niche game.