“The diffusion concept is incorrect. There are multple sources and multiple sinks. So it is a problem that is different in kind to a simple atmospheric source and sink idea.”
Captain #2 doesn’t understand that the concept of diffusion is exactly a dispersion of flows working in various directions and at various rates. That is what a random walk entails, and why master diffusion equations (such as Fokker-Planck and Navier-Stokes) model this phenomenon so well.
What I have done in my modeling is add another level of uncertainty and dispersion to the diffusion coefficient, and what this does is simplify the analytic form.
You swung and missed badly.