Lee wasn't against necessarily a tactical defensive battle, but if he was going to force that he would have had to get between Meade and Washington, his real hope was to force Meade to force march to him, while he was already concentrated, and to defeat Meade in detail. Unfortunately, he didn't know Meade was as close as he was, because he was expecting to hear from Stuart. I'm not going to rehash the Stuart issue. I recently read Wittenberg's book and it was very eye opening. You can equally blame Stuart, Lee, and Robertson. Though my takeaway from it is that Robertson bears the most blame, as he should have immediately told Lee that the AoP was on the move north when he saw it move. Stuart should probably have left Hampton in charge of that force honestly. Back to original point. Another factor is if Hill would have followed orders Lee would have concentrated his men at Cashtown, which is where they were supposed to concentrate, but Hill/Heth got dragged into a fight and Ewell marched to the sound of the guns.