Wow. I just resd this thread and got a ton out of it! Thanks so much!! I agree with you that the heart of the game is a puzzell of multiple layers and that the grid is the most perfect solution to it given the confines, or rules, of this medium. I also think that is what gives this game it`s apeal to so many.
I have had SC4 for a while and have been doing grids to learn the mechanics of the game, but not to your extent. I will be working them out with more depth now!!