This is definitely one of the most enjoyable sequences of the game. It wasn't all that hard, I'll admit, but it was somehow very satisfying. Must've been all the enemies rushing at you, and all at once. Felt like I was in a true battle. And yes, the enemies were easier to bring down, but you wouldn't want to be overwhelmed by a group of them; much more strategical if you killed each swarm as they came upon you, since they probably were programmed to follow you all the way down (lest they'd go against Ghirahim's orders). At least the enemies varied, including a new type: Bomb-chucking Bokoblins.
"The Horde" did get harder as you went along. Barriers obstructed you from advancing further, and tougher foes appeared out of thin air. The Moblins seemed less a challenge; I'd gotten used to them in Lanayru Desert. It was the Stalfos that inconvenienced me the most, namely the four-armed warrior. Then I thought about tactically placing bombs in front of them and that cut them down one by one. Setting oneself in a field where the usage of various items can come in handy makes the battle seem like a puzzle in itself, and the diverse challenges that Ghirahim's forces presented allowed for this.