If he had water, and was able to use it before Crocodile could kill Gaara, he could win I guess.
Shukaku is not a big deal though.
Oh, and Aura, well Crocodile can create city-sized sandstorms which can strip people in them to bone, if he has enough sand. Actually, that is one advantage Gaara has, he can make new sand. Though I would argue that would just make it easier for Crocodile to win.