If you believe this, then why is it so hard to believe that Lee may have had knowledge of what the intentions of Lincoln and Winfield Scott were in regrards to the southern states? Remeber that Winfield Scott was the same Winfield Scott who had planned with Andrew Jackson to force South Carolina to back down from the Nullification Crisis in 1832 by using the same Tactics.
Was Lee sticking his head in a bucket and totally unaware of what was going on? I don't believe so "IF" he was being "Groomed". I Know that this may be "speculation" as some have accused this as being. But if a man is being "Groomed" then the man doing the "grooming" should have been sharing his confidences with the man he was grooming.
Lets remember that speculation is not a "Bad" thing. History is not complete because not all things have been written down. It is like a study of the Bible. What proof do we have that Christ is who he is? It is simply a belief isn't it, There is no physical proof that this belief is factual. That is why our salvation is by faith not by sight. The same is true with history. You have to look under the "Rock", or read between the lines, to find the greater meanings.