Curious to see how the production handles the actual battle...
Is the Vale's army still there?
Unless i'm mistaken dragonglass is useful against Walkers but not more effective against the dead than anything else, so those spiked battlements and fancy axes aren't going to give anyone an 'edge' when the endless wave of screaming clawing corpses comes blasting along.
I'm expecting Dany's Unsullied to be kind of ineffective against the dead. Long stabby spears and phalanx or shield wall tactics do not seem like they will be effective when your enemy just takes the hit and pulls itself up the spear to claw your face off.
The Northmen should be ok as far as the actual soldiers/warriors go, but the 'we're not soldiers' dudes are going to break like wet paper bags. Dothraki... could go either way. They're used to deserts and plains, not snowy hills, but that may be a detail too far for the show to go.
I dunno, but maybe a crypt full of bodies isn't the bestest place to be when you're fighting guys who raise the dead. It may be just an assumption that the Walkers have to kill people before they raise them. On the bright side maybe we'll get to see Ned and Robb again
Really the only way to win this is to target the Walkers whenever possible so the dead they control drop. Again, wondering whether the writing team goes that route. It would be sort of silly if they didn't considering that was Jon and co's entire tactic when they went beyond the Wall last season. They flat out stated their whole plan is to nail the Night King for that very reason, so it's not like they don't know this already 'in world'.