Isn't that to be expected? I mean KoA puts far more emphasis on combat. It's not my cup of tea (too silly and over-the-top), but given its more central role in the gameplay I'd expect it to be more complex and developed.
We already have a thread about KoA http://www.gamesas.com/topic/1333487-kingdoms-of-amalur-reckoning-thread-the-second/, you're welcome to repost the link in there if someone hasn't already brought it up.