Sort users by userID by default on users.php

You can use pre_get_users since WP 4.0.0

function my_user_sort( $query_args ){
    if( is_admin() && !isset($_GET['orderby']) ) {
        $query_args->query_vars['orderby'] = 'ID';
    }
    return $query_args;
}
add_action( 'pre_get_users', 'my_user_sort' );