I think the track layout is fine.. if it were a real mine. The routes more or less make sense and would provide carts access to important facilities. I don't think a mine would spend that much money on rails, but if they did, that's probably similar to how they'd lay it out.
Problem being, mine cart tracks serve a different purpose in TF2.. they don't exist to be realistic, they exist to guide the player. Look closely at Valve maps.. while they do use extra mine cart rails, they're usually half buried in a displacement so they don't draw too much attention. The tracks that Valve considers "gameplay important" are generally quite distinct.