Could more minelaying submarines have slowed Axis offensives?

The counterfactual gives Norway a dozen modern submarines able to guard fjord approaches with torpedoes and mines. More aggressive commanders might have positioned those boats near likely invasion routes before German forces entered the fjords. In the Far East, dispersed minefields could have delayed Japanese amphibious operations even where no mine was actually present, because every approach would require caution or sweeping. Small navies could gain leverage from weapons that continued shaping enemy decisions after the launching platform moved elsewhere.