I mean that's a legitamate argument for why it WAS a decisive battle, I just took issue with you saying it should be ranked for how decisive it COULD have been. No issue with your last post.
I understand what you are saying.
I feel the Battle of Midway Island was the most decisive because of the dire situation the USA was in. We have to look at the impact of both victory and loss would have on both sides.
Had the USN lost the battle, not only was the mid-Pacific open to the Japanese but, with a base at Midway Island the Japanese Army was in position to invade the Hawaiian Islands. At the very least, to put completely out of operation Pearl Harbor as a useful naval base. The loss the battle means there would have been no viable opposition to the next series of Japanese moves, to the Hawaii Islands, New Guinea, the Solomon chain, possibly New Zealand, etc. If the Navy was lucky, a loss at Midway would only mean the US Navy would only loose one additional carrier (two carriers sunk) and the one surviving carrier (probably badly damaged). One damaged carrier plus the USS Saratoga available a couple months later would be no real challenge to the Japanese Navy. The Americans would have no battleships, a few cruisers, a few destroyers and, a submarine force with rotten torpedoes. The carrier would be low on the number of fighters available, a few dive bombers and, no torpedo bombers! Experienced pilots would also be in short supply. In essence, a navy in name only, definitely in no position to assert any opposition! American losses at Midway would take a long time to replace. American manufacturing is beginning to increase but, far from the juggernaut it was a year and a half later.
The carrier Saratoga was being repaired (from a torpedo hit) and a overhaul -having her 8" guns removed in Seattle and arrived to late for the Battle of Midway. The USS Ranger was the largest carrier in the Atlantic (17,000-tons), was being used to ferry Army P-40s and provide air support in Operation Torch, in North Africa. The USN had a couple of escort carriers -converted oilers in the Atlantic but, five of these could not replace any fleet carrier.
The Japanese Navy loss at Midway, its carrier navy never fully recovered. They never got back the numbers of highly skilled pilots, aircrews and, maintainers. A victory for the Japanese at Midway meant their experienced aircrews, pilots and, maintainers would still be able provide great air support for the Japanese Navy, it could continue to exert its will. The war in the Pacific would last year
s longer before the USA would be in the position of invading the Japanese home islands -in late 1947.
American losses in other battles of the Pacific such as Leyte Gulf would have set the Pacific effort back maybe a year or so. Where as American war production was now up and swamping the Japanese in material produced. The Japanese plan for Leyte Gulf was to break through, slaughter the invasion beaches and the amphibious forces there. They might have been able to damage or destroy Adm. Olendorf's battleship support fleet but, the Japanese knew they had no way of dealing with Task Force 58. The Japanese loss the first Battle of The Filipine Sea against Task Force 58. They were not able to deal with Task Force 58 at the Mariannas (The Great Marianna's Turkey Shoot) and situation since then had only gotten worst. This is why they were willing to sacrifice the remainder of their carriers north of Cape Engaño.
American losses at Leyte Gulf could be replaced.... difficult but doable. Japanese losses were not replaceable.