Both of which are plot holes. Madara's rods negate ninjutsu, so Yin seal shouldn't have worked. I shouldn't even bother with the giving Obito chakra nonsense, conidiering not once, but twice, we see her say she is out of chakra, when she is healing shikmaru and Naruto, yet suddenly Kishi decides to ignore that in order to make her relevant.Wow.
Hinata would put Sakura to work...... ? This is what I mean't by giving Hinata too much credit...
Sakura was tanking attacks from Madara... And dishing out attacks he'd rather not get hit bye... Giving more chakra than a Rikodo Naruto clones(50% of Naruto's chakra), and you say Hinata would be a CHALLENGE, or DIFFICULT.
Sakura could beat Hinata with Katsuyu, I'll give her that.