How can i order get_the_tags?

There are always workarounds to implement the sorting:

Add this function:

function se_sort_tags_alphabetically( $tags = array() ) {
    if ( $tags ) {
        $sortData = $sorted = array();
        foreach ( $tags as $i => $tag ) {
            if ( empty( $tag->name ) ) continue;
            $sortData[$tag->name] = $i;
        }
        krsort($sortData);
        foreach ( $sortData as $index ) {
            $sorted[$index] = $tags[$index];
        }
        $tags = $sorted;
    }
    return $tags;
}

Then use:

$post_tags = se_sort_tags_alphabetically(get_the_tags());

Hope that helps.