You are correct. The water passage associated with the output of the intake water to the T-sat will give the best average eng. temp. In the scheme of things, you really shouldn’t see any significant temp difference of water anywhere in the intake. Water temp in the intake is a product of head output temp so the temp should be relative uniform unless you have head or gasket registration issues.
If you have what appears to be too high a temp, validate the actual reading. I use an IR Temp gun to measure and validate what I think I see on the cars gauge. I look for possible causes of temp measurement error once actual temp is verified. If reading high, its most likely an incorrect temp sender unit or instrument voltage regulator. I don’t ever remember finding a temp sender that will cause high temp readings. Maybe low, but not high.