Cerberus = THREE headed monster by CruzaderJC

We know from the Dharma plans that the Smoke Monster and its vents refer to CERBERUS. Now Cerberus is the Greek/Roman Three Headed Beast that guards Hades, the Underworld.

From the season premiere, we now know Fake Locke (Flocke) is the Smoke Monster. BUT, we were also hinted early on that there are more than one smoke monster. For example, when Locke first saw the Smoke Monster, we didn't see the Smoke Monster, but Locke said it was "beautiful". The second time Locke sees a Smoke Monster, he is frightened and it tries to kill him. Moreover, they refer to the smoke monster as the guardian of the temple, but now we see the Ninja Others defending the Temple from Flocke. Therefore, we can conclude there is at least more than one manifestation of the Smoke Monster.

Now if you can follow my logic, could this show be about the THREE HEADED defenders of the Underworld? Could Jacob be one of them? Who is the third?

My Theory: Jacob, the Man in Black, and an unknown entity are the three "heads" who protect the gate to the Underworld, the Island being this gate. Jacob continues to bring people to the Island, to prove to the Man in Black that humans can be inherently good. Something goes wrong and humans discover the Island and begin tampering with the supernatural forces of this Underworld Gate. Now the Man in Black wants to go back to the Underworld, but Jacob won't let him, so Man in Black devises an elaborate plan (possibly the entire 5 seasons of Lost) to get Jacob killed, and now there is one less "head"

Who is the third head? Good = Jacob, Evil = Man in Black... Third = Science?

Is the point of the Others to discover the reincarnated version of the Third Head?