The Candidacy...is for Smokey by Team Jack

My theory is that Jacob is recruiting for candidacy, for Smokey.

I think Smokey is not the light but plays the role of the ‘security system’ of the light/energy. The energy being evil, birth, rebirth etc. As long as there is smokey, the energy is protected (from exploitation) and can be contained.
Jacob is recruiting for a new Smokey. If there’s a new smokey, his brother can ‘go home’ or die but live in an alternate timeline.

The brother (MIB) does not care about the energy or to protect the energy. He wants to go home and not spend his eternity as the smoke monster. The only way he can go home is if someone else becomes Smokey (the last candidate standing)…he has no faith that there will be a last man standing because they all kill each other off. He’s trying to find a ‘loophole’ that will free him of the position of Smokey – without putting someone else in that position- which would free the energy to the rest of the world.

Jacob has faith that one of the candidates will remain and will then assume the role of Smokey (by entering the tunnel of light). Smokey will then continue to act as the security system, keeping others from finding the energy and finding a way to release the energy into the world.