Wrong...Manu brings the little things....Like a couple or three steals a game, which can translate to a 8 - 12 point swing in the Spurs favor.
Williams picked up the slack for Barry with his 3 pointers, but no one picked up the slack for all the little things that Manu does that translates to wins.
Not saying with Manu the Spurs would have won for sure, but their chances certainly would have increased.
Manu brings things to the team that you can't teach and you can't practice. It's called a will to win, and only one guy on this team can actually will this team to a win in a tough game.