The bombs used in Japan near the end of WW2, were not hydrogen bombs. They were said to be atomic bombs. Hydrogen bombs weren't even acclaimed to have been developed at that time.
But what the bombs used in Japan really were, was TNT or some form of plastic explosives. The reasons why they couldn't have been nukes, is listed in the article in the OP.

Your first two sentences are correct. But your last two sentences are
complete nonsensequestionable. The bomb that fell onto Hiroshima had the yield of about 15 kilotons of TNT. How are you supposed to carry 15 kilotons of TNT on a plane? 15 kilotons of TNT is far too heavy for a single plane to carry. You need to account for
not only a single mushroom cloud over Hiroshima and another one over Nagasaki
which is easy to do if there is one plane.
Hmm. If nuclear fission and nuclear fusion cannot be made into weapons, how does the sun work? Does the sun even exist?
What about nuclear power? Does a nuclear power plant gets its power from magic instead of nuclear fission?Regards,
-Joseph Van Name Ph.D.