If I were the owner of the above themed layout;
A local to switch the industries at the southern end of the layout, probably a GP38 or SD40 if this is NS themed (though here I am seeing a -9 on the local just about every day; the poor economy seems to have made those older locos less "economically viable" sadly, I miss that old high nose SD40)
A dedicated mine run, this would likely have heavier power, once again if NS, SD60s, 70s, or -8s. It could have newer SD70Ms or -9s, but variety is the spice of life for layouts. And of course, top gons!
Some run through freights for variety and to complicate movements. Any combo of "new" NS power pulling all sorts of things. Intermodals seem to appear everywhere.
Any variety of MOW, track inspection, you name it, could appear and complicate things.
This sounds like a fun layout, actually!
