Which begs the question, if Mance knows Castle Black has all of these defenses along the Wall, why doesn’t he send all of the people capable of climbing it over at another unguarded spot. Then he’s got hundreds, if not thousands of more raiders attacking the Night’s Watch from behind with Tormund and the Thenns. They would probably easily overwhelm the defenses at the bottom and then they could just open the main gate from below.
basically they want to walk the army through, not eveyone can make the climb. Which would have made sealing the gate, much easier to defend since they all could have defended the fort from the inside attack with Ygrette and then focus on not letting the strong ones climb the wall
A counter argument would be that if they had sealed the gate the Wildlings would have no desire to attack at castle black and would assault from another place spreading the nights watch too thin. By having a weak point you invite the enemy to attack there and can organize a better defense.
Is there any reason to suppose the wildlings would have known the tunnel was sealed before they got there? With a solid enough defense of the gate on the first night of battle, they’d have been in place and focused and committed to this point, only to find on the second night that the tunnel was completely impassible, and have to entirely redesign their strategy after the battle had begun.
I imagined that they would just detach part of the wall, killing everyone hanging on it and everyone under it, while making a mountain of sharp ice that the Wildlings would have to get over before even getting to the newly-made very smooth wall. But this way is cool, too, in that it turns Wildlings into red mist.
the battle of Blackwater, Tyrion had been meeting with all the blacksmiths in the city and got them to forge a huge chain which he had laid across the mouth of Blackwater Bay. When stannis’s ships sailed in, the chain was raised, which destroyed a huge number of ships, forming a bridge of broken ships across the mouth of the bay and meaning Stannis’s fleet couldn’t flee, then he launched wildfire at them via catapult.
A bigger concern is why he wasted Tormund and co on his first attack when he probes the defenses. A better strategy would have been to throw literally everything he had at the gate (we saw only a few dozen barrels of stones/ice/oil on top of the wall, so dropping shit wouldn’t work for long, and the books support this), and then this massive frontal attack would coincide with the attack on Castle Black from the south. We saw that most of the defenders were taken off the wall to fight in the castle, meaning that Mance would’ve had a pretty easy time attacking the gate, especially because one giant almost got through. He’s got more giants and a fuckload more men — throwing everything he had at the wall, right off the bat, would probably have won him the battle right then and there.