"Fat Man" and "Little Boy" were code names selected to mimic the physical appearance of the bombs. "Fat Man" was a spheroid surrounding a spherical implosion bomb. "Little Boy" was a much smaller, cylindrical gun-assembly bomb. Cabal naming conventions are more bizarre to entertain than Martians writing their names on the bombs.

There were zero radiation/ fallout problems from the bomb bursts because the fallout drifted away and was dilute enough not to be a problem. This is typical for a tactical nuclear weapon...but not the story that was propagandized to inspire fear in the public over nuclear weapons and technology. Likewise, the Japanese survivors did not demonstrate an undue incidence of cancers. There was no "should have been," since this was the first and only experience of the situation. There is still controversy over the "zero tolerance, linear dosage" assumption that predicts cancers and deaths. The data seems to indicate that "hormesis" applies to radiation exposure as to all toxins: there is an exposure level that is actually optimal for human health, either higher or LOWER exposure is less healthy. This means that some low dosage of radiation is actually healthy for human beings. Not too surprising, since we live in a low radiation natural environment.

It took the Japanese two bombs to come to their senses and realize they had no future prospect of winning the war, and that surrender was the wiser choice. Two bombs. They couldn't come to that realization with one bomb, which is a measure of the sway held by the military in their counsels.

I am sorry, but it seems the reason you don't believe things is that you don't know things.