You are certainly right there ChristiaanJ.
There is no need to complicate the question with such things. In fact nothing useful will be achieved by doing so.
To simplfy the question as much as possible let's start by considering a metal cylinder which is closed at the front end and has a convergent propelling nozzle at the back end.
If the pressure in the cylinder is greater than that outside, then the air in the cylinder will be accelerated rearwards through the nozzle. This will produce a forward acting force which we conventionally call thrust.
But the force acting on the nozzle will be acting rearwards, so let's call it drag. Or if you prefer let's call it the Rearward Acting Force or RAF (a pretty appropriate abreviation really... the RAF always was a rearward acting force).
Now the thrust isn't pushing forward on the nozzle, so where exactly is it pushing forward?
If we can solve that one, then we can look at the slightly more complicated case of a zero by-pass jet engine where the front end of the jet pipe houses the exhaust unit and the turbines.
No maths required here, just a little bit of imagination and no emotion whatsoever (GRRRRRRR).