Game of Thrones

[hollodero]

Now I'm anything but a war strategist. Unlike most Americans I guess.... so to anyone who has those huge miniature battlefields at home - what about the tactics here? The artillery pretty much was useless, why not have it less exposed and use it first before attacking? Also, why launching said senseless attack first, were there too many Dothrakis? Why go for an open field battle when you got defense systems in place? What about luring the night king out with Bran and having no real trap there? Arya pretty much stepped by on an impulse, but no one else had anything prepared, no Dragonstone knife or whatever. Instead, Theon just shouts and runs at him and dies. Also, the walls weren't protected at all it seems. Not even some big trunks rolling down or anything really. And they waited for the dead to come to said walls and then suddenly it was all frantic when they did. Archers there! You there! Everyone run around! We couldn't have possibly prepared for this while waiting!
And finally, how would that many people survive in the end. The dead army already was everywhere for quite some time, even strolling around within the halls. How?