Theoretically or not, the japanese navy being unharmed is basically implausible. The only way to not be harmed by this invasion was a full evacuation. The US navy may have lost a few ships at pearl harbor, but not enough to stunt their commander's skills. The japanese had Yamamoto, but the US had Nimitz. The japanese not to mention were losing oil at an alarming rate, every US carrier the japanese destroyed, 3 more would take it's place. Every japanese carrier the US took out, nothing would take it's place. Not to mention the japanese were fighting a losing front in china. So the only way they could've gotten out unharmed is if a miracle happened or US commanders became incompetent for the remainder of the battle. Even if the japanese pulled off a miraculous victory, the japanese would have to deal with reinforcements. The US had millions at their disposal and a thriving economy. Japan had half of the manpower and a quarter of the economy the US had.
Yamamoto wasn't the only great naval commander with great skills, you forget that there were guys like Nagumo with great skill and tactics, which did run barely noticed...
To be precise these are Japanese navy commanders present at ww2:
Hiroaki Abe (1889–1949)
Masafumi Arima (1895–1944)
Shigeru Fukudome (1891–1971)
Boshirō Hosogaya (1888–1964)
Matsuji Ijuin (1893–1944)
Toshihira Inoguchi (1896–1944)
Shigeyoshi Inoue (1889–1975)
Seiichi Itō (1890–1945)
Kakuji Kakuta (1890–1944)
Mineichi Koga (1885–1944)
Teruhisa Komatsu (1888–1970)
Nobutake Kondō (1886–1953)
Takeo Kurita (1889–1977)
Kameto Kuroshima (1893–1965)
Jinichi Kusaka (1889–1972)
Ryūnosuke Kusaka (1892–1971)
Gunichi Mikawa (1888–1981)
Osami Nagano (1880–1947)
Chūichi Nagumo (1886–1944)
Shōji Nishimura (1889–1944)
Tomoshige Samejima (1889–1969)
Satō Tetsutarō (1866–1942)
Shigetarō Shimada (1883–1976)
Kōichi Shiozawa (1881–1943)
Kantarō Suzuki (1868–1948)
Sōkichi Takagi (1893–19??)
Takeo Takagi (1892–1944)
Ibō Takahashi (1888–1947)
Takarabe Takeshi (1867–1949)
Sadatoshi Tomioka (1897–1970)
Soemu Toyoda (1885–1957)
Matome Ugaki (1890–1945)
Tamon Yamaguchi (1892–1942)
Isoroku Yamamoto (1884–1943)
Edit why does this list doesn't include Ozawa?!? Wiki is a bad source of information😐
