Would the Germans have even built Tirpitz if Bismarck had not been sunk?
Tirpitz had already been launched and was fitting out.
The Tirpitz and Bismarck were built pretty much concurrently. There is a school of thought that Bismarck should have waited for Tirpitz to complete and work up, then gone to sea as an actual fleet. Had they then met up with Salmon and Gluckstine out of Brest, it would have been quite impressive. Utterly useless, but impressive.