Pershing insisted in useing 1916 style tactics which the British and French pointed out, had not gone to well on the first day of the Somme, and at Verdun and Nivelle offensive. Hence the high AEF casualties in the last months of the war from August 1918 to November 1918 when they were fully engaged.I'm not the one who mentioned 4 or 5 Divs - but the whole of the AEF most certainly weren't decisively engaged in 1918 so listing every Division is disingenuous. Your 14 divisions at St Mihiel chimes with my 'low double figurers'.
The US contributed a great deal late in the war and their manpower was a decisive factor in eventual victory. However the US experience cannot be compared to that of the Empire, France, Germany or Russia. As a morbid example you need look no further than 1916 when the British Army sustained more casualties during the Somme battles than the AEF did for the entirety of their involvement in WW1. I say that not in a competitive sense but simply to highlight the different levels of involvement and sacrifice.