To non-English people the town parochialism does seem pretty odd.
If Manchester was in Australia, people within the Greater Manchester metro area would just say theyre from Manchester. A city stretches until its urban sprawl ends, the concept of 2 separate cities neighbouring each other doesn't exist. Technically there are multiple cities within the Sydney region, but most from (City of) Parramatta still has Sydney as their primary local identity.
If Sydney was in the UK, it would likely have 7 or 8 distinct cities each with a unique sense of identity.