You do realise that people in the same tier can be much stronger than eachother, it doesnt mean everyone there is EQUAL, just assumed to be in a fair fight.
Heck, maybe Full power Cinder is higher than Low 7-C, but of course was only defeated by the Silver eyes most likely due to this crippling weakness.
Glynda wasnt even attacking Cinder primarily, she was trying to take down the plane, so we really cant scale. But she was enough to make Cinder and Torchwick retreat, if that means anything.
Oh lord, not another one saying how Qrow wasnt taking things seriously. Look, the whole episode was about introducing those two characters and what they can do. They showed their fighting skill ALONGSIDE their personalities during that fight, as well as neither Qrow or Winter truthfully allowed to kill. This means Qrow really only came off as playful, as if he was "holding back", to make the audience know who he is, but that really doesnt mean he was holding back. I honestly dont know how RWBY characters can hold back, they dont have power levels they can lower like DBZ.
Theres also the fact that Winter barely shown the full capabilities of her summoning, shes most likely destroyed way more things in the past, so she should have a large army behind her. She was also being playful and trying to annoy Qrow with those birds, so maybe she was holding back to. There is also the fact on how Winter was finally trying to get serious, but was "cut off"... by Ironwood, because there we see Winter was barely even using her glyphs till the end of the fight, maybe to climb up walls, but not much else. Oh,and i dont even think Qrow landed a clear shot at her, while shes able to land numerous...
Qrow = Winter = Low 7-C , i mean, i know we all love Qrow more than Winter, but the show clearly indicates itself that they are equals, while doing so through a display of personality aswell.
