The Wun Wun thing is flat out ridiculous. They just don't want you to think about how badly they handled that. In Hardhome he completely demolished about a hundred zombies or whatever with a tree trunk, barely had a scratch on him.
If Jon had any intelligence at all he would have formulated a battle plan around Wun Wun wielding a tree trunk, of which there's a ton of different ways to do it. The only real threats to him are archers, pikes, and cavalry and even the archers can basically become a non-threat to him if he's carrying something that can block the arrows.
If Sansa would have told Jon about the Vale, all he has to do is use their calvalry to flank the archers and use his own men to take out the cavalry. And then Wun Wun could just wipe the floor with literally every single infantryman including the pikemen with the tree trunk he used in Hardhome. Even with Jon rushing out to save Rickon they still would have utterly annihilated Ramsay if Wun Wun would have had a weapon. It's a game changer. I loved the battle scene but the contrivance to get it to play out like it did is really annoying.