I disagree with some of the pretenses here primarily that higher level math directly equates with a better performing student. I went to grad school for chemical engineering with 1/3 US students and 2/3 foreign all from China and India, and I will agree that their skills when it came to even engineering math (e.g. calculus, differential equations, linear algebra, numerical analysis) all surpassed what I and other domestic students knew.
But I think this is because of a fundamental difference in evaluating what problems are important. During my undergrad, memorization for a test was thought to be a pointless task and not worth doing (because in the real world, you can use Google, textbooks, whatever you want to accomplish the goal). Tests were structured to require extra thinking, problems could be formulated in a completely different way than found in the homework, or worse, the questions could nigh-unsolvable and require the student to explain how they would go about solving it if they weren't able to. However, in grad school, most of my tests relied on memorization of certain fundamentals and derivation methodologies to succeed. Guess which group performed better on that?
But what about skills that are not so easy testable? Like communication? Or thinking about a problem outside the box and not approaching it from the exact same way as everyone else? Many modern engineering problems are not just solved by use of complex mathematics; formulation of a problem, simplifying the problem where appropriate, solution methodologies, thinking about time constraints, monetary concerns, interactions with less technical people, and communication of results are all part of my daily job. Solving a problem using personal knowledge of PDE's may help occasionally, but knowing how to use tools when appropriate and knowing how to communicate is worth far more ultimately.
Anecdotal evidence is anecdotal, and YMMV.