Hm, the change helps indeed. I did this in my code:

    p = argparse.ArgumentParser(description='…', add_help=False)
    g = p.add_argument_group('Options')
    g.add_argument('-h', action='help', help='show this help message and exit')
    g.add_argument(………
    g = p.add_argument_group('Arguments')
    g.add_argument('file', ………
    args = p.parse_args()

Maybe adjust the documentation to match? As it stands, https://docs.python.org/3/library/argparse.html is somewhat helpful, but https://docs.python.org/3/howto/argparse.html is totally confusing.