Yup, this is exactly correct it has to do with the order of the operations.

I guess if Moose would first create a data structure instead of accessors, and then, upon for example, getting to the no Moose or __CLASS__->finalize() part, create everything in one go, the approach could be independent of the order of the declarations, something which I find less confusing.

Unfortunately no Moose fires at compile time, so that is not really usable as a "end of class" marker. I also pondered a  __CLASS__->finalize() type thing as well but forcing people to explicitly say "compose my class now please" is problematic in a highly dynamic language like Perl. It would also make runtime alteration of classes extremely tricky since the user would again be forced to say "okay, done with the alteration, please apply it". So while I don't 100% like the "compose as you go" approach we ended up with it does mean that at any given time in your program your classes are still valid. And while this does create some edge cases like this (most of them are role issues like this too) it also allows for a lot of other things to be possible. Everything has its trade offs.