Tale of Two Wastelands

Hi, was just linked to this mod, which sounds awesome (though the installation looks daunting).

I was just curious how game flow is supposed to work.
Are we to play through FO3 and DLC and then hop the train to NV?
Or the other way around?

And how does it handle the NV intro if you started with FO3?
I'm guessing we don't get reset after being shot in the head.