Having left footprints on the ground of a number of coal mines, I’m going to approach this from a different angle.
First, if possible, get information about the subject mine, especially the rail facility that served it. Track patterns, approximate rail size (heavy, medium, light - dont obsess about specifics) and appearance. In my experience, the track around collieries is pretty much on uniform ground level, and the level pretty much corresponds with the tops of the ties. Also, the rails are not perfectly straight and/or perfectly parallel. They might have been once, when freshly laid, but years of operation and misadventure take their toll.
Because of that, ‘Everything on one level,’ look, sectional track on roadbed is a poor choice for modeling yard facilities of any kind. Sectional track without roadbed is a bit too perfect, and at the same time has funny-looking ends. In my opinion, flex track is the best choice for getting that, ‘good, but not perfect,’ look.
It is possible to mix and match different sizes of rail and different types of track with wild abandon. All it takes is getting inventive with connections between rail ends. Avoid abrupt kinks and dips and all should be well.
In my own work, I use a variety of flex track from different sources combined with hand-laid switchwork. As for age/experience, I got my first Lionel set at the age of five (months) and shifted to HO while Truman was POTUS. I have been married (to the same woman) for almost 53 years, and my great-grandsons are six, four and two.
Chuck (Modeling Central Japan in September, 1964 - with collieries moved over from Kyushu)