If, on the other hand, you're talking about 'self-inflicted' casualties, then Gen. U. S. Grant has to be considered in that negatively rarified air as well.
Lee had massive casualties during the 7 day battles and at Gettysburg... and at Chancellorsville, even if he won a great victory.
Grant only had losses that big at Shiloh... until moving east.
And even if Union forces in north Virginia and later around Richmond lost more men that Lee during the last part of the war Lee still lost more men in total.
But across the war Lee inflicted way more casualties on his enemy than the number of men he lost... some of it by union stupidity. But in other cases it was good CS planning and operational decision making that caused it.