Действительно странно. Вот здесь написано что такой возможности нет
https://docs.microsoft.com/en-us/dyn...vs-overloading
Цитата:
Overriding vs. Overloading
Overloading is where there is more than one method with the same name, but the methods have different signatures (return type or parameter lists or both).
Overriding is where the superclass's implementation of a method is altered by the subclass's implementation of the method, but the signatures of both methods are the same.
X++ supports overriding, but it does not support overloading