Kronik, 5 str translates to 3.75 attack and a chance to up your fstr as well as 5 dex = 3.75 acc with small crit bonus.
The +1-2 fstr near counters that atk and then couple it with the acc bonus, haub wins for pure DD.
Nin is better off with haub because it is more dependent on acc while receiving a higher bonus from the fstr relative to its base damage (lower the base larger percentile change). So while a nin might lose out on 7.5 atk, it gains 2.5 acc, which it usually needs more than atk, on top of the fstr.
Plus you could get haub +1 significantly easier than togi +1 making it a comparison of 12acc/atk (15-17.5) 6str/dex where haub would win every time.
Before the 2 hand updates this piece was better than Hauby for SAM's, after the original update Hauby became the better piece yes. However after the 2nd update this piece once again became good for SAM for normal attacks, still use Hauby or Hachiman Domaru for WS's.