[Hitman]

But as a result, you can save your own skin by being able to look around without killing your solution

In the german TDC you also can. The Kaleun ordered "Lage folgend" or "Lage nicht folgend" and by switching a knob the TDC was un-linked from the optics allowing to take that look around (A blue lamp indicated the unlinked to optics status).

Or, as in the Dick O'Kane technique, you can set up your attack, then look for the present position of the target without worrying about your chosen attack bearing being ruined by moving the scope

You can also do that with the german TDC. Set up the solution, aim the optics and then unlink the TDC so that the optics are free to rotate and the solution is fixed at the point of aim previously chosen.

The real American TDC also had an input for target length and calculated offsets for any desired percentage of spread

The german TDC also had that You can see the dial for " Gegner Länge" (Enemy length) here (Highlighted in pink):

It's all in your mental attitude toward the equipment you are using

Yes to a big extent, but not completely. The american TDC was superior to the german TDC, not because the german was bad, but because the american was the state of the art in those years. The germans created deliberately a simplified TDC to help more novice sailors and IWOs get used to it quickly, so they could pour out new crews faster. Also, because the whole attacking party in the submarine was more reduced (Space limitations) and a simplification of the tasks was highly desirable.

The beauty of the american TDC was the incredible accurancy it could provide, thanks to the position keeper and the ability to directly enter ranges determined with active sonar and radar. This wonderful machine was developed in a time when the doctrine thought that getting close to a target would be very difficult due to enemy ASDIC and low submerged speed in submarines, and it came as a response allowing deadly accurate shots from 4000+ yards

German doctrine called for close combat action in night surface attack, and hence their TDC was more simplified and with a higher priority in being able to quickly switch between targets, leaving precision in a second row due to the short distance the attack would be done.

Our main problem is not just the attitude as you point out, but the fact that recreating such a complex tool as the US TDC would be a game in itself, and unfortunately the simplified version we have in the game lacks many key features like the spreads based on target length you mentioned. I have solved that with a printed table for various target lengths and distances, but still it would have been awesome to have it calculated in game by the TDC