I agree with your assessment about envy. Grant's greatest claim to fame is that he fought against Lee, but only won one battle against him even with his lesser numbers on April 3rd, 1865. In every battle in 1864 Grant left Lee's army in command of the Battlefield and manuvered away from Lee. He could only do that because of the size of the Union Army at the time. Had Lee's army been equal in numbers and support as Grant's, I wonder what would have happen then?
In fact I know what would have happened. Lee would have crushed Grant when he dividied his army at the Wilderness to move on to Spotsylvania. Once Lee realized that Grant had split his army to race ahead to Spotsylvania he would have simply over run those left behind and cut off Grants forward elements at Spotsylvania from their supplylines. Grant got away with a lot of his manuvering because he had a superior army in numbers.