I agree. The Crawler and Knight, to a lesser degree, seem to fill the role that Drones and Skirmishers did without their gameplay annoyances. Drones were fidgety, making them difficult to target if they couldn't make their minds up between the ground and the air, and the agility of the Skirmisher wasn't really consistent, making their jumps kind of difficult to predict. Crawlers have those jump packs that smoothly elevates them up, making it easy to predict and target. The teleport ability of the Knights is incredibly well telegraphed with the visual effect pointing towards their destination (I seriously think this is one of the most genius things I've seen), so you're not going to get surprised because the AI made an illogical leap.
Brutes, I think, work very well as a miniboss, but not as infantry, especially the hammer chieftain. If they axed Brutes as a normal enemy entirely, instead just using them as special moments with the chieftains, that could make for some really rad moments without the annoyance that comes from the infantry versions. Pushing them up into the same class as the Hunters could make a little bit of Brute go a long way. The original four Covenant races are a really fantastic set of enemies, but I think there's a place for the "rushing boss" style of enemy (like the hammer chieftain and gold Sword Elites) where there maybe isn't for a class of faux-Elites.
I think that emphasis on the hammer chieftain over the fuel rod variant is important. I don't know what was going through some of the campaign designers' heads with Reach. Fuel rods are not fun to fight en masse, just like Brute Shots to a lesser degree often weren't, yet we see instances where you can have three or four homing fuel rod shots coming at you at once. I really, really hope they dial down the number of enemies with AOE weapons.
