I admit I know -zero- about WW1 era french ribbon bars, but those look US style to me. Many Doughboys went home with the French medal on their chests and got the WW1 victory rosette later. Wartime decorations for gallantry seem to have been worn ahead of all other medals, in spite of country of origin. The US military was a little more lax and sparse in these matters.
The idea of ribbon bling was to impress girls and cadge free drinks when you got home. 99% of Americans were not and had no intention of being professional soldiers, so they were a little more relaxed.