Overriding is fine. The issue comes with polymorphism and would even without inheritance per se, as can be seen in Go where interfaces provide polymorphism without inheritance.
You're right, the issue comes from polymorphism, and from use of polymorphic values when the specific class cannot be determined statically. But this is sort of the point of polymorphism, can't do much about it, except maybe caching the looked-up value(s) when looping over a polymorphic collection.
