Irvin McDowell studied and taught tactics at West Point and wasn't afraid to attack. I don't think it was really his fault that he lost Bull Run, but his improperly trained men. Once his army had training and experience, he maybe could have used or even mastered flanking attacks similar to Jackson or Sherman. Sure Grant would have probably been a better leader, but maybe McDowell could have gotten the war to a better start if he had been in command of the Army of the Potomac.
____________________ That old man...had my division massacred at Gettysburg!"
- George Pickett said these words to John S. Mosby shortly after paying Lee a visit in Richmond
"Well, it made you famous"
- Mosby's reply to Pickett
Studying and teaching tactics kinda loses its luster when the lead is flying. That's a whole nuther ball game. Strangely enough, McDowell was leading the Army of Northern Virginia; Beauregard was leading the Army of the Potomac.
I think in general you are right. McDowell was put in a near impossible position. He had not led soldiers in any capacity in more than ten years and had never led anything larger than a regiment if I remember correctly. Everything he did as an Army commander was on the job training. Plus he had the unenviable position of having to attack with generally untrained troops whereas the Confederates simply had to parry uncoordinated Federal attacks with their own untrained troops. With that being said, McDowell expected too much of untrained volunteers. His plan was not bad, but, he should have known that a night march to an attack position coordinating between two separate wings of an army was far beyond his and his subordinates capabilities. Part of being a good commander is understanding what your Soldiers are capable of and using them within those constraints. Cheers!