spline patching horror

 From:  Rogurt
Hello all

I really try hard to get the grip on spline patch modeling. But even the simplest of all basic models gives me results other than I expect.
I have 3 identical circles in the 3 dimensions with the center perfectly aligned. Since the network command outputs a big mess when selecting all 3 circles I trim them with one another mutually and create the network patches one by one. The result should be a perfect shading sphere, no? I mean all the tangents should still line up since I did not tweak anything.

What am I doing wrong? Are there some golden rules I can follow when it comes to spline patching?