Second, Grant could not have landed 50,000 men in the Carolinas for a number of reasons - one, the political ramifications, two, it would have left Washington too vulnerable with nothing to interpose between the capitol and Lee, three, Grant already had Butler on the peninsula for very much the same purpose - to push immediately against Richmond while the AOTP took on Lee and held them while Butler took the capitol.
This failed because Butler was a complete imbecile who got himself bottled up on the peninsula and essentially sat there doing nothing.
Keep in mind, it also shows von Moltke's failure to understand modern warfare. He was of the same mentality of his time that thought warfare consisted of maneuvering the enemy out of position and siezing territory.
That was outdated thinking. Grant was the first truly "modern" general in thinking. He knew that siezing territory meant nothing with enemy armies in the field. Grant's intent (and strategy) was to annhilate the Confederate armies in the field. Grant was after the Confederate armies, not "Richmond", though he knew an attack on Richmond would force them to fight him.
The Wilderness wasn't a battle, it was merely the opening engagment of a 30 day long battle. It was about getting hold of Lee's army and simply trying to annhilate it. Period.
That's what Sherman was about, and that's what Grant had in mind for all five armies that were supposed to move out on May 4th. Butler f-ed his part up, Banks f-ed his part up, and Franz Sigel f-ed up his part too. So it really ended up coming down to Grant and Sherman.
Appomattox is the testament to the fact that Grant's overall strategy was sound. It worked.
Grant is one of only two generals on either side to accept the surrender of an enemy army - and he accepted the surrender of three enemy armies in their entirety. That speaks to his record. Sherman is the other, who accepted the surrender of Joe Johnston's army shortly after Lee surrendered at Appomattox.