I almost always run cables like the Merckx in the first pic, behind the bars, crossing over the stem, with the rear cable behind the front. I find this usually supports the rear cable in such a way as it doesn't rub against the stem, but this may be different for larger frames with correspondingly longer front brake cables. Also, the pic shows what I call a "racer cut" in terms of cable length and I usually trim housings a bit longer than that, which helps to keep the cables above the stem. I have occasionally switched sides for the front brake control, but I often find myself forgetting that I have done so, and this could lead to a problem in a panic stop, though it hasn't yet, for me. With a setup like that of the blue Peugeot, I would most likely route the front bake to the left lever and keep the rear brake cable on the right side, both behind the bars. I have an aversion to running brake cables on the front of the bars partly because they invariably rub against the bars, but more because I setup so many cheap Schwinns that way back in the 1970s to keep the cables away from the extension levers that it still makes me shudder when I see it, today.