There might be colleges where the teaching is better in stats or math departments. At the undergrad level, the rigor might be higher in the stats department, and more appropriate for people who will be taking graduate level econometrics later. I think your classmates could be smarter in the math and stats departments, making it easier for the teacher to be more rigorous.
'Transition to Higher Math' or 'Intro to Writing Proofs' courses might be added to the list.
Some econ grad students said they had to use point-set topology. Some colleges have a little of this in an undergrad real analysis course, but some might not.
Some researchers are using numerical methods, which is rarely taught in econ, and even when it is, the rigor and teaching might be better in math.
Stochastic processes or stochastic calculus courses are sometimes recommended.
The OP's view might be correct, for all I know, for someone trying to start an academic career inside the econ departments. However, I doubt it is always correct for other related career paths. I have seen comments here saying that at least some Quantitative Finance employers can prefer hiring people from math, stats, computer science or even physics or engineering, over somebody with a PhD in economics. If that is true, then taking more math department courses than what is in the OP's list could be a worthwhile investment toward a type of finance/econ career.