Modeling a Model Railroad - A step to far?

While I was working on the track plan and the buildings I figured it would be a reasonable idea to add some freight cars and locomotives to the project. In hand I own a Rock Island SW9/1200 and 2 Santa Fe CF7s. In the near future they will be joined by 2 DRGW RS3s so I need to represent one of each of those three plus an assortment of 40' and 50' boxcars/reefers.

I initially hemmed and hawed about doing this but in the end since I was going to build the model an extra bit of visualization wasn't going to hurt and I might be able to see problems that I hadn't anticipated pushing these little blocks around.

So I took some measurements and built a bunch of blocks to represent the freight cars and engines out of styrene. I was going to leave them white and then decided that was just to plain and a little color was going really help me see things better (basically the whole thing is just white with a few black and blue lines).

Since I was painting anyway I went ahead and tried to a little bit of flair to everything trying not to go to overboard on the whole thing. Which means I did resist cutting down the locomotive hoods, at least right now.

I was to busy painting to take in progress pictures so here is the finished bunch (still on the sticks).

Row 1: Rock Island SW9/1200, Santa Fe CF7, DRGW RS3
Row 2: 3 40' Generic Boxcars and 3 50' Generic Boxcars
Row 3: 3 40' DRGW Boxcars, 3 50' Generic Boxcars
Row 4: 1 40' DRGW Boxcar, 3 50' DRGW Boxcars and 1 50' Generic Boxcar
Row 5: 7 40' Generic Boxcars
3 Locomotives and 24 Boxcars. From an operational standpoint the 50' boxcars won't get used very often, 40' is going to be the common size. Figure the time period as late 1950s early 1960s.