The freedom of information in an open society as opposed to restriction of information of a closed society is part and parcel of what earns the societies their designations. The axis societies were much tighter controlled than western ones. We had American companies doing business with Germany until the day war was declared by Hitler!
With Japan, the problem was not only one of a more guarded society but an extreme culture difference which made it next to impossible to imbed spies or to have Americans in trusted positions during peacetime. They had hundreds of merchant ships of which we had no knowledge at all. Yes, they did purchase some of them from European countries and some of those dimensions would have been known. But masthead heights, funnel arrangements and heights, and cabin configurations were easily and frequently altered.
I'll bet the Americans sneered when they encountered the multisyllabular unpronounceable gizmo I have called the OLC GUI device in U-505. Of course they failed to recognize the sheer ingenuity of the process! The Americans had radar, which made all such primitive nonsense obsolete. Except that both the Germans and Americans had salt water, which has unfortunate effects on electrical technology.
But the ones evaluating U-505 were desk jockeys, dealing with theory of devices used in best-case conditions. Technology is an addictive drug which sometimes blinds us to its limitations. If anyone not a desk jockey was evaluating the German targeting device, I'll bet they sneered only until the next time their radar failed at a critical moment!
You also have to keep in mind that the American military system punished risk-taking and enforced adherence to protocol, while the German military emphasized front line initiative, giving commanders in the field much more latitude to make decisions. On land, the result was that one German unit was equivalent in combat effectiveness to approximately 3 American similar units. They were simply much more flexible and unpredictable than we were.