Tell me why this won't work, I have to be missing something.

As it stands now, create 1st overworld portal. Upon entrance of said portal, the nether is created. Then, the 1st portal is placed, and moved to a safe location, if necessary. Then, upon exiting 1st Nether portal, a second overworld portal is created to correspond to 1st nether portal's location.

Now, why not, when generating the 1st nether portal, generate the world first, then "slide" the world to adjust the location of the 1st nether portal to correspond a safe location, and assign that location the matching coordinates so the portals link up?

Am I explaining this well?