Chapter 7. Method Overriding and SUPER:
You may override methods in the default Perl 5 OO system as well as in Moose. Unfortunately, core Perl 5 provides no mechanism for indicating your intent to override a parent's method. Worse yet, any function you predeclare, declare, or import into the child class may override a method in the parent class simply by existing and having the same name.
This whole paragraph seems to say that Moose has none of these faults. But even in Moose a method may override simply by existing and having the same name since the override keyword is optional