Think you are correct. McClellan was a soft war man. Use just enough war to get the Confederates to the conference table. McClellan supported that view as the Democrat Presidential candidate in 1864. He was also one of the few officers that had seen what the killing power modern infantry weapons could do. he had been an observer in the Crimean war.
“he was far more willing to tolerate the loss of life than was George III.”
He was also smarter than King George III in that he believed one war at a time was enough.
Balderdash. Lee and Grant fought to win, and would do whatever it took to achieve their objective because winning as what was important to them. McClellan fought not to lose, because his reputation mattered more to him than victory did.
The British were trying to run an empire, and they were spread a bit thin. Their arrogance may have occasionally bit them in the @$$, but it is a large part of why they were so successful at building that empire.