I, also, expected a manual for the expansion. I was on the fence about buying this game until the expansion came out, and it mentioned capturable golems. Then I started to play, realized that I had no idea what I was doing, and started googling.
However, having gotten used to the game and some insights on the development and community, I think that it is just as appropriate to have a wiki. The only manuals that have ever been worth reading were blizzard game manuals. The tutorial is far more effective in this situation, complemented by the wiki and forum.
I think that this game does have a bit of a learning curve, which is a barrier of entry to the product. I'm not suggesting it be made simpler, because I don't like to play simple games, but perhaps the mechanics of the game, statistics even, could be written down. I have been spreading the word about this game to my friends, and I think confusion is their biggest hesitation.
Oh, and to reply to the person that was mentioning thinking about the game being almost as fun as playing it, that's very true. To any chess player club level or above, theory craft about the game can be just as amusing and occupying as implementation. Many of us lead lives during the day that do not include ai war, are not easily amused by human social drama, and would much prefer thinking about statistics and strategies. It is the same thing for Dungeons & Dragons players involved in campaigns.