Thank you for your response.
Perhaps my choice of words was misleading: after all, the advance on both days was not marching as in a parade.
With that adjustment, I believe my comments reflect my understanding. Lee's plan- on both July 2 and July 3, 1863- was to attack Cemetery Hill using a pincer movement: Ewell would attack from roughly the north, while Longstreet attacked from roughly the south.
On July 2, Longstreet attempted to move his troops "by a route concealed from the view of the enemy" to take up a position to advance northward. "General Lee's orders were to guide my left by the Emmitsburg Road."<James Longstreet, From Manassas to Appomatox: Memoirs of the Civil war in America. (Philadelphia: J.B. Lippincott, 1896), pp.366, 367.>
On July 3, Pettigrew, Davis, et. al., certainly advanced roughly perpendicular to the Emmitsburg Road, while Armistead, Garnett and Kemper advanced first to the road, then turned left to advance roughly along it.
On both days, Lee's plan failed. And on both days, the advancing Confederate forces 'lost their way', straying from their intended path. On July 2, because Sickles lay unexpectedly in their path. On July 3, because of the horrendous, deadly gauntlet of fire they were subjected to.