Address field order on Contact's "edit" page
I think you will have a significantly easier time just reordering the fields with a little jQuery in a custom version of the template you referenced above.

For completeness... You can see the sequence function here: https://github.com/civicrm/civicrm-core/blob/5dde2c09c10513a22464e8c4abcb6b4ca17fc1cb/CRM/Utils/Address.php#L288