I doubt the veracity of these quotes.
I agree. I don’t think Eisenhower or LeMay were in the decision loop. As for Leahy and the rest, why did they not make these objections to Truman himself?
The Imperial Army had no intention of surrender, even after the second bomb.
The Imperial Navy, which by this time effectively ceased to exist, agreed with the ministry that surrender was the only option.
After the second bomb, Hirohito himself made the decision to surrender. He believed the US possessed many such weapons and refused to allow Japan to be vaporized.
Even then, some in the army refused to surrender and launched a plot to kidnap the emperor and continue the war.
Cooler heads prevailed, and the army was forced to abide by Hirohito’s decision.