The Legend is not completely and I can prove it! The Legend of the TriForce is saying (or at least I think it say) that if Ganon will get his hands on both the Triforce of Power and the Triforce of Wisdom he will be indestructable and nothing can stop him from taking over Hyrule. But in Zelda 3 - A link to the past Ganon has not only the Triforce of Power and the Trifore of Wisdom but he also has The Triforce of Courage but Link can still defeat him! If anyone does not agree with me send me an mail with your version. Look below for possible solutions to the problem sent in by other people:

Suggestion #1
We have got one suggestion that in Zelda 1 there were only 2 triforces (the triforces should have been named due to tehri rectangulat shapes not the fact that there are three of them). In Zelda 2 the third one was dealed away somewhere and you needed all three to awake the princess. He claims that it´s Zelda 4 that messes up the story by giving Ganon the 3 Triforces. According to the legend Ganon never appeared before Zelda 1 either.

Suggestion #2
Another opionin is that Ganon doesn't have complete control of the triforce until the light and dark worlds are merged and the last great hero (Link) is destroyed.

Suggestion #3
The legend states that the world would be remade to reflect his soul. And in Zelda 3, Ganon's wish for power was not completed. He did not wish for indestructibility, he merely wished to be powerful, to be granted the power to rule the world, or to rule the world. Therefore, since the tri-force was in the process of granting his wish, Link didn't give Ganon or the Tri-force the time required to make Ganon's wish a reality.

Suggestion #4
you see, you've got it all wrong. the reason that the triforce story seems messed up to you is because you have the thought that all 5 zelda games continue in some way......but the truth is, THEY DON'T! trust me, i know (N.O.A. sources). the reason is that each story is supposedly a variation on the LEGEND of Zelda (except for link's awakening, that could be considered a sequel to link to the past). from what i know, each is a different story on what the legend of zelda might be.....you'll find more about this on zelda DD (?2?).
Orlando