As I've indicated that doesn't actually make any sense. The Greeks probably lost 50% at Thermopylae, while the Persians only lost 10%. They had the 'victory' only because they actually took the pass.
Who's talking about "victories"? I was explaining why I call Lee "Lee the Butcher".
I'm not a military historian, so this is my very general observation.
Without making an ultimate judgement, its seems to me that part of the problem w/ the question is that, by-and-large, Lee fought way more defensive engagements than Grant, especially when they were mano y mano at the end. Generally speaking, defensive engagements are easier to fight and offensive actions take higher casualties. I don't think its a coincidence that when Lee was on his strongest offensive action (Gettysburg) that he had his most significant failing.
Again, this is my mid-level understanding, feel free to politely show me the errs of my ways/reasoning.
That's a very good by-and-large way to put things. Usually, the tactical offensive has the consequence of higher expected casualty rate (per Lanchester's law, which is the only thing close to a valid dictum in military theory): the usual claim is three to one.
Lee is also extremely well known for having preferred the tactical offensive. In the Seven Days' battles, the ANV was on the offensive in every single engagement; same at Second Manassas (Lee's greatest victory, by the way), Chancellorsville, and Gettysburg. The tactical offensive has some attendant advantages that can be good force multipliers - like possession of the initiative (and therefore, usually, concentration of force) - and, more importantly, one almost always needs to take the offensive in some form to actually win. In some circumstances (again, like Second Manassas) the ANV benefited from those force multipliers. During the second half of the battle of Chancellorsville, and again at Gettysburg, it was however drawn into relatively disorganized and uncoordinated attacks that did not make full use of concentration of force, losing the tactical offensive's most significant advantage.
Some of these same problems afflicted the Army of the Potomac in 1864. Its command structure was relatively new and untested, and much confusion resulted, especially from Grant's early disagreements with Meade. (These were ironed out by 1865, such that the Army of the Potomac was able to mount one of the best-run maneuver campaigns in the history of modern warfare, namely, the Appomattox campaign, which is frequently and unfairly slighted on the grounds that it was against a weakened and doomed enemy - false - and victory was practically inevitable at that point.) Coordination suffered as a result. Other tactical problems were relatively new. It was in 1864 that you really get the first instance of the sort of constant fighting that eventually became well known in the World Wars: two armies, in more or less constant contact, spending virtually all of their time either marching or fighting. Nobody was prepared for the strains of such a sort of campaign; everybody was used to the stop-and-start actions that usually constituted warfare. And in such circumstances, the exhaustion that resulted invariably favored the defender. At the same time, though, from an operational standpoint, that constant fighting was
necessary. The campaign had to keep going, partly for political reasons and partly for attritive reasons. Exhaustion, and the poor coordination that was its result, ultimately stemmed from that.
So we see multiple instances of Grant ordering grand tactical outflanking maneuvers and such, but poor staff work and sheer exhaustion on the part of his own troops generally prevented these from being effective before Lee could respond. This became especially prevalent during the later parts of the campaign, e.g. the march from Spotsylvania to the North Anna River. At least twice, the Federals missed the opportunity to destroy Lee's army in detail (once on the march, once in battle positions) because Grant's troops were simply too tired to carry out their orders. Should Grant have been aware of this? Almost certainly. He may very well have been. But if they had even the slightest chance to succeed, attempting such maneuvers was necessary if he wanted to accomplish the goals of the campaign.
Ugh, that got away from me pretty quickly...