That's why I made an exception for widebodies, although I accept that "making an exception for widebodies" more or less undermines my point. But I claim that,

That's why I made an exception for widebodies, although I accept that "making an exception for widebodies" more or less undermines my point. But I claim that, for example, you can't realistically have a 737 layout that isn't 6 seats wide in coach — and that means the width of your coach seats will be whatever width fits 6 seats plus one gangway.