What if the Kriegsmarine decided that building large, expensive battleships was pointless for Germany, and built 100 Type VII U-boats instead of Bismarck and Tirpitz?

(NB: the figure of 100 is based on the tonnage of Bismarck - which is about equal to 50 U-boats. But 50 U-boats might cost more than Bismarck, I'm not sure about that.)

Anyway, the U-boats did far more damage to Britain than Bismarck and Tirpitz ever did. The big battleships were scarcely cost-effective.

Even together, and with Scharnhorst and Gneisenau as well, Bismarck and Tirpitz had no chance of beating the British Home Fleet in a Jutland-type fleet action - they were far too heavily outnumbered for that. And as commerce raiders they were overkill - the pocket battleships were good enough for that.

But having an extra 100 U-boats available in late 1940 might have tipped the Battle of the Atlantic in Germany's favour - since at that date Germany only had about 60 historically, which was nowhere near enough to cripple Britain's trade.

Opinions?