Do you really believe that Virginia's fire-eaters would have joined the Union army? Really?? If you do, I don't think there's any point in continuing this discussion.
It's a question I've wondered many times. Why does it upset some people so much to think that there might have been Confederates who were motivated to fight for some other reason than slavery? But I've really quit wondering by this point. They exist, and no amount of evidence or logic will change their mind, and that's that.