Eh, Warcraft and C&C were both based off C&C-maker Westwood’s earlier Dune game engine. Neither is very innovative (especially when you consider WC’s roots as a Warhammer knock-off*). And I think significant changes to the gameplay mechanism or to the story-telling qualify as innovation, or at least substantive development.
What I find really interesting is your assertion about simply making the game more complex/difficult. I feel the exact opposite; the improved troop AI and other changes made WC3 a lot easier for me to manage than the first two, although the missions and multiplayer were balanced to keep the difficulty up. It was one of my favorite things about the game. I was very put off of Starcraft’s multiplayer because I just couldn’t keep up with other players when it came to micromanaging my armies, and WC3’s gameplay developments almost completely eliminated the problem by shrinking the overall scope of battles, improving ai, adding autocast spells and formation movement.
The ability to tab-select all units of a given type in my currently selected group made using special abilities a lot easier as well. Being able to buffer move commands in a chain to direct troops then leave them alone, set building spawn points on my hero so new troops automatically meet up with them, improved hotkey features and being able to set groups of units to be called up by manually set hotkeys (ctrl-grouping) made managing my forces and economy very simple.
To make a long story short (too late), I found WC3’s gameplay design shifted the focus away from how skilled I was at using the interface, to how skilled I was at planning and combat-tactics (you know, the point of a strategy game). Although, not as well as WH40K: Dawn of War has (I love that series).
God, I know. Whatever Will Wright’s doing to keep them from screwing around with Maxis, please let it continue (is it Blackmail? or does he just have the CEO’s balls in a remote-controlled vice?). Did you know that he had to struggle with them to get the first “The Sims” game released, because “no one wants to play a game of real life.” That must have been one huge egg on that exec’s face, am I right?
*Mind you, I am a huge fan of Warcraft’s lore, but I’m not going to pretend that it didn’t get it’s start from a certain franchise.