Hugh L. Scott was CSA;
What alternate choices were there to Pershing for command of the American Expeditionary Forces (AEF)? Additionally, would a different AEF Commander have an effect of any kind?
Hugh L. Scott was CSA; he asked for JJP to come to Washington in March for cosultations, and with Newton Baker's blessing, let him know he'd start with a small staff (~200 officers and men) which would initially get the 1st Division (under William Sibert, initially) and then build up to a corps, army, and army group.
Scott was very capable, but both he and JF Bell (who commanded the Eastern Department and was a former CSA) were not young; Scott was born in 1853 (as was Tasker H. Bliss, who served as CSA from 1917-18 and on the Supreme War Council in 1918-19) and Bell in 1856. Pershing was born in 1860; Peyton March - who served as CSA in 1918-21, was born in 1864.
There was some lobbying for Leonard Woood, for obvious reasons, who was the same age as Pershing, but although a former regular was not a West Pointer and had a fairly irregular career path.
Pershing was the best choice.
Hunter Liggett, RL Bullard, and JT Dickman, the three army commanders, were basically the only real alternatives; Liggett (born in 1857) was older than Pershing, as was Dickman (also 1857); Bullard, born in 1861, was a year younger.
Best,