Woah, hold it, does this involve actually using TESIV bits and resources? Because Bethesda really cracks down on people importing stuff from one TES game into another.
Until someone finally bothers to take them to court and point out they can't do that, which is probably what would happen. But that's not a discussion for here.
Great concept, but to be realistic one might need to do some research on landscapes and ecology, and what things affect the distribution and abundance of species. Additionally, you'd want to research a bit of geology.
I don't think Morrowind involved all of that so much, and it worked alright.
Admittedly, with some research, you could come up with quite the interesting world.
Fractals provide one method for generating river outlines, mountains, and forests height and distance distribution. Check out my post http://www.gamesas.com/index.php?/topic/1100340-fractal-geometry-making-realistic-landscapes/page__p__16084915__fromsearch__1entry16084915, or just watch the video I linked to. It's a pretty lengthy program (about an hour?), but you can see it all for free and without commercials. I recall that it is more towards the later segments that show the link between predicting the length of shorelines use fractal math, and how vegetation distribution is fractal in nature. Applications: being able to generate realistic vegetation in the landscape, along with other features (river, mountain) = less time spent having to hand-place trees and shrubs.
Aye, fractals have been used for landscape generation for quite some time. They don't always work, but certain ones work great for coasts, rivers, and even trees themselves. Overlaying a fractal over the Morrowind terrain heightmap could add the detail necessary to counter expanding it by 2 or 4 times size.