You guys aren't serious right? Cliff Is the Lead Designer of the game. He Is responsible for every aspect of it, beyond producers he is the final word on what goes where, there's nothing in the game that he hasn't made prior approval to be there.
He sold the original concept to Epic, he also told the crew what art direction to go in, he made final decisions on the single and multi-player aspects of the game. By what I know the games his baby, pre-engineered by Cliff and helped along by his crew.
So yeah, I'd say he knows what he's doing, Gears of War is a pretty damn fantastic game.