You would think from the role-call of Nazi quantum physicists (that's Jordan and Heisenberg and...possibly nobody else...and even to keep Heisenberg, Himmler's mother had to intervene...) that the Germans would have had a hard time assembling a good team to do the work and build an A-Bomb. Unfortunately, Heisenberg, the only person to bother to do the calculation, was off by a factor of at least 100 in his over-estimate of the amount of fissionable material required. Significantly, nobody in the German bomb program checked that calculation and they assumed they had about a thousandth of the amount of fissionable material required while in fact they only needed about 10 times what they had. Planning for using fission assumed the "bomb" would weigh about 1000 tons or so. A ship-sized bomb. Apparently that was what they were working on sort of, though not very hard.