By late WWII the ability of US subs to shoot was so much better than the average U-boat, because the range was solved perfectly by the SN radar ( periscope Mounted single pulse 3MM wave length. target speed resolution was within a tenth of a knot on Us boats when the Germans were still eyeball estimating speed . The torpedoes carried verses the % hits is very revealing. The allies had full techinical support from ASWORG and several other matematical scientific groups. While Doenitz stuck with the same size staff and staff structure he had at the begining of the war. German improvments were evolutionary as they lost boats and battles. The allies were revolutionary applied science as they outstripped the German productivity per boat at sea (Doenitz's measure of success) once they solved the torpedo fuze problems and depth keeping.
When looking at better subs you need to look at net combat result and survival rate. A weapon system analysis is called for not merely a few disjointed facts.
The Axis forces constantly fielded equipment with outstanding single attribute characteristics that were consistently beaten but the Allied weapon systems.