Adjust which tempalte a page uses with a function?

This might work:

add_filter('page_template', 'custom_page_template');

function custom_page_template($template){
  // check your permalink here
  if(get_query_var('pagename') === 'stories')
    return locate_template(array('page2.php', 'page.php')); 

  return $template; 
}