Stan,
I think that if Johnston was in command many things would have been different. Not only was he a great tacticion, but he was one of the best stratgists on either side. I will step on a few toes here, but if he had been made general in chief like Grant was, the federals would have really had their hands full. As for Pat Cleburne, he could really think on his feet. He was at the train station on his way to Knoxville I think when he recieved word to return with what troops he still had who had not been sent forward to Knoxville to take command of part of the troops at Missionary Ridge. He returned, made a survey of the area of his responsibility and by day light was ready to defend the ground. Many Federals were killed and many more were seriously injured by what he did.
As you may or may not know, most Irish did not have much love for the English becuase of the potato famine and the way the English treated them in general. That is what lead to the founding of the Fenians if you know who they were. I would think if the had their way (the Irish) he would have been treated like a Unionist in most areas of the south where there were many Irish.
Frank