Likewise, if the slaves had been freed and could vote, they may have voted for the "liberating general," McClellen or a Southerner who was at least personally opposed to slavery, Lee.
Jackson was a bigger opponent to slavery then Lee. He actually ran a sunday school for black children and taught them how to read and write.
Neither of which, as you've pointed out, necessary mean that someone is opposed to slavery.
You seem equate treating slaves well with opposing slavery. They do not equal. Jefferson Davis, from what I've heard, was considered to a "good" master. He was
still a master.
Lee, on the other hand, said, in effect, "I don't want to be a master." Even if he had not treated his former slaves well (he did), they were still not slaves.
A scenario of what happened in 1860-64 would still be needed to understand this primary race.