One of the things that provided some really dramatic pictures last Saturday was the placement of the third engine mid-train instead of ahead of the caboose. It facilitated some great pix with all three engines.
When John Craft ran a three engine train some years ago, the third engine was ahead of the caboose and almost impossible to get in a picture with the two engines on the point. Tom Gildersleeve has one picture at Coxo with the two engines on the point and you can barely see a feather of steam from the helper way back ahead of the caboose. But the engine placement was done that way because it was considered prototypical.
So one question might be is there a historical precedent for the DRGW using a third engine midtrain. All the pix I've seen of three engine trains have the third engine ahead of the caboose. However, I believe there are some pix of two engine trains with the helper mid-train (which is what Greg Scholl did on one charter). And it would not surprise me if in the early years of the pipe boom that the DRGW experimented with all kinds of arrangements.
A second question might be....does it matter. Because it clearly makes for some dramatic pictures.
JBW