@elliot I think this could be simplified by adding a filter to the code so we can set the menu position when the menu item is registered:
$parent_page = add_menu_page( $this->settings['title'], $this->settings['menu'], $this->settings['capability'], $this->settings['slug'], array($this, 'html'), '', apply_filters('acf/options_page/menu_position', null));
The list of available positions is here:
http://codex.wordpress.org/Function_Reference/add_menu_page#Parameters
e.g. To position it after “Dashboard” you can set the position to 3:
add_filter('acf/options_page/menu_position', function() { return 3; });
What do you think?
Thanks!