Grant was a mediocre general who never flanked if he could make a frontal assault. He was a butcher, famous for his use of cannon fodder long before he took command of the AoP. Both Ft. Donelson and Vicksburg were won by the U.S. Navy and overwhelming resources. If, in the West, Grant had been fighting the ANV generals he criticized (or men like Cleburne, Taylor, and Forrest) instead of nitwits like Bragg and Pillow, he would have had his lunch handed to him......ala the Battle of Cold Harbor. It took him nearly a year to defeat Gen. Pemberton's starving army. Below is a fine example of Grant's close personal friend (who was "better than Jackson") leading troops during the Vicksburg seige.
Battle of Chickasaw Bayou
On December 26, 1862, three Union divisions, under Maj. Gen. William T. Sherman, disembarked at Johnson's Plantation on the Yazoo River to approach the Vicksburg defenses from the northeast while a fourth landed farther upstream on the 27th. On the 27th, the Federals pushed their lines forward through the swamps toward Walnut Hills, which were strongly defended. On the 28th, several futile attempts were made to get around these defenses. On December 29, Sherman ordered a frontal assault which was repulsed with heavy casualties. Sherman then withdrew. This Confederate victory frustrated Grant's attempts to take Vicksburg by direct approach.