Sakuke's susanoe is not the weakest, obito only broke through sakuke susanoe because it was the weakest form which was the ribcage type in order to conserver chakra and nothing more, sakuke only let his gaurd down. the susanoe hɑsn't been shown to the full lenght, remember sakuke susanoe change when he was fighting with kakashi, which kakashi to be afraid, but for low chakra it disappears.
sasuke susanoe can change it form to either pure arrow or black fames arrow, when was fighting with kabuto he didn't use black flames arrow for pure arrow, check manga .
The form sakuke awaken when fighting with kakashi, had a covered face and with black flames he would be invisible