The point is he didn't need to use them against Crocodile.. True, he STILL hadn't invented them yet, but the point is he managaed to beat Crocodile without them yet he barely beat Lucci WITH THEM. An incredible power increase, which, if Luffy had them in Alabasta would have obliterated Crocodile easily (this is completely undeniable, Luffy seemed much more physically powerful than Crocodile in the fight, let alone going at Soru speed which there would surely have been no way Crocodile could keep up), yet against Lucci, he BARELY managed to win and let me emphasize bearly. After the fight, Luffy couldn't even move which didn't happen against Crocodile. That's how much he was damaged evev WITH his incredible power increase.