I'm sure it depends on the student; I sure remember my physics major girlfriend struggling with Lagrangian mechanics in her advanced classical mechanics course. 3 decades after doing basic classic mechanics I can see the utility of Hamiltonian mechanics but I'm not at all sure I'd want to tackle it (chemistry major here ... I wonder where we fit in the hierarchy).
That's what I remember as well; if you limit it to science, I've always heard Math > Physics > Chemistry > Biology.
I've never heard of a ranking that mixes science and engineering before the one you mentioned; at my school, at least, there was generally mutual admiration, with math and physics ranking above any engineering field.
