Hard peaked at #8
We can't compare that to the other songs you listed which were real flops.
But Man Down is the only correct answer.
It's one of her best songs. The vibe, the vocals... everything was right.
It fits her perfectly Idgi why it performed so poorly.
Man Down didnt really underperform. Neither did Hard. A US only single mainly targeted for urban airplay that still went top 10. Wait Your Turn was a PROMO single.
But in terms of quality.
Wait Your Turn > Man Down > Hard >>>>>>>>>>> California King Bed.