Did I already screw up?

So started story mode, and got to Rank 5, about to hit the Battle of Wan Castle....Yet I still only have sword & spear unlocked - no gauntlets in sight. Looking it up, apparently I needed to beat Zhou Cang in the Guangzong battle, which I could have sworn I'd managed, but guess I could have missed it.

Question is, do I have any way of getting them now? Or do I need to finish story/restart game to try again.