The word "arch" comes from Latin. It's added to any kind of noun to show it's superiority towards it. (Bishop, archbishop, rival, archrival) It is used in a many languages. In my mothertongue (Dutch) it is "archi". An example would be "archislecht". Slecht means bad, so the word archislecht would roughly translate to very, very bad.
Seeing as the word is spoken in many languages (in most languages pronounced as arch, some as ark) one must use the word as it is ment to be used in ones motherlanguage. In English that would be arch.
In this sense, when does a word structure or pronunciation become correct?
In Australia, we structure sentences and pronounce words differently to people in America, and likewise England.
Are we doing it wrong, is America wrong?
Or are we all right?
Has our common language been transformed to the point where it could be considered a different language? (Dialect?)
I know expat Americans living in Australia often have a hard time adjusting to our use of language and making sense of what they hear. Allot of this comes down to our pronunciation and structure.