sort custom post type by count

i have a shortcode which shows posts that have this slug(taxonomy “models”)

This is it:

function tfuse_popular_brands($atts, $content = null) {
    extract(shortcode_atts(array('title' => '', 'multi' => '', 'link' => '', 'text_link' => ''), $atts));
    $arr_ids = explode(',',$multi);
    $args = array(
        'hide_empty'    => true,
        'parent'        => 0,
        'child_of'      => 0,
        'fields'        => 'all',
        'orderby'       => 'count',
        'order'         => 'DESC',
        'include'       => $arr_ids
    );
    $terms = get_terms( TF_SEEK_HELPER::get_post_type().'_models', $args );
    // for order in initial order
    $term_arr_ord = array();
    foreach($arr_ids as $key=>$ord){
        foreach($terms as $unord){
            if($ord==$unord->term_id) {
                $term_arr_ord[$key] = $unord;
                continue;
            }
        }
    }
    $out = '';
    $out .= '<div class="brand_list">
        <h2>'.tfuse_qtranslate($title).'</h2>
        <ul>';
            foreach($term_arr_ord as $term){
                $logo = tfuse_options('maker_logo','',$term->term_id);
                if( $logo !='' ){
                    $out .='<li>
                            <a href="'.get_term_link($term->slug,$term->taxonomy).'">
                            <img src="'.$logo.'" alt=""></a>
                        </li>';

                }
            }
        $out .= '</ul><a href="'.$link.'" class="link_more">'.tfuse_qtranslate($text_link).'</a></div>';

    return $out;
}

I try to order by how much times post contains this slug but no luck. Please help