The Numbers and the Flash Sideways by Jsephus

This is my first theory posting. I think it has been brushed on by others, so sorry if I step on any feet. I don't think I've seen it put together quite like this though.

In S6E4 "The Substitute" we got such a difinative answer to the numbers that alot of my Lost friends considered that mystery to be pretty much solved. They represent possible "candidates" for whatever (Jacobs replacement?). I cant accept that to be the final answer.

The numbers have always linked to the Valenzetti Equation, which was commissioned to predict the end of humanity. This is where my theory starts. I think that the Flash Sideways are not showing us an alt-after but an before-alt. This is the first time through, well, time. Jacob has not met with The Numbered yet, and nuged their lives to the island. What we are seeing now is how their lives should have been. We are going to see by the end of Season 6 how our beloved losties are responsible for bringing about the end of mankind. As to how a Dr., fugitive, lucky business man, married couple, old crippled dude, and former torturer go about doing this is beyond me. All I know is these people have to be on the island for man kind to live on.

I realize there are lots of holes in this, and I am probably way off but the logic keeps yelling at me;
Numbers = End of Humanity
Numbers = Jack and company
then Jack & Co. must = End of Humanity, right?

Please cut this all to hell and tell me how wrong I am. Or if it rings true with you, feel free to use it and expand.

Cant hold my excitement, only 12 hours left!!!