Bruce, Doug & all who were kind enough to take time to reply:
I went to the RRTrak site and read the stats. I will have 3 NG's on my layout: Fn3, Fn2 (I believe that is O gauge @1:20.3, I'm new enough that the numbers don't stick well, yet. Sadly, I'm old enough that they may never stick! And whatever "S" NG is called when built to the same scale.) In other words, one scale, three gauges. Anyway, I read all the data on the page. It seems to me that I have to buy a package for all three gauges which puts the price out of reach. Also, I don't like 'fiddling' with software because I'm no computer expert. And to do what I wanted with what they offered appeared to involve a lot of tweaking. I'll be handlaying all track.
The size of my layout isn't fixed to a final dimension, which is why I have a bit of leeway and wanted to see how things might be massaged. For that, a compass and a pencil will do with a much shorter learning curve.
What brought the question to mind is, the benchwork will be a deep 'U' shape. I was wondering if, by selective compression of widths, it might be made with a middle leg. (An 'E' shape). I doubt it due to the radii of the G gauge track, even though I intend to run short engines and rolling stock.
The layout, as presently envisioned, will consist of a lead mine (S NG), a logging operation (Fn2 plus dual trackage with the Fn3, a feature that's always intrigued me). The final site will be a RR yard. Lastly, after the actual track is laid, I hope to include a light rail line somehow. However, that last is far in the future. Perhaps impossible.
I sincerely thank those of you who took time to express your opinions.