Yamamoto would have not negotiated a surrender. One reason he was sent to sea was the fear that some junior Army officers would murder him for being perceived as not aggressive enough. That was a real fear that Japanese senior officers and politicians carried with them. Junior officers carried out many assassinations.
The Imperial Army just before Hiroshima was spoiling for a fight with the US Army. They had never really fought us. We fought Japanese naval ground forces mostly in the Pacific. The Army would have killed Yamamoto if he’d counselled surrender.
“The Imperial Army just before Hiroshima was spoiling for a fight with the US Army. They had never really fought us. “
There were plenty of Army units fighting in the Pacific war, I think people just assume that everyone was a Marine. There were as many as 22 Army divisions assigned to the Pacific war, about a quarter of the Army’s total manpower. Marine Corp had around 6 divisions.
https://www.armydivs.com/pacific-theater/