Had to make a GH account to jump in here. Been with this set since the beginning and my early impression regarding novelties was similar to what is stated above. I love the more "scientific" ones, but I also really love the variety. I was a huge fan of GMK Copper for the same reason, really different novelties and the only thing they all had in common was Copper... the theme of the set.
I think these go in a similar direction, where the images are all quite unrelated... except that they are all made of Iron (which is the theme of the whole set). There is definitely a sub-theme of weapons/armor that has popped up in the kit, which personally is not my jam, however, there are a LOT of people so far that have responded well to that sub-theme, so it would be silly to cut them out. Also with KAT, the kits are a lot less expensive than GMK, so why not throw a bunch of novelties in there and then you get to pick and choose which you like?
If you don't see any commonality between the novelty kit, you need to look again. If you get it, but would still rather the novelty kit be tailored to just the novelties that you would buy... well I don't think that's a reasonable expectation of any set designer.
Part of the fun of this set (and Copper before it) is trying to figure out what ties the novelties together if you don't know the name of the set. You should be able to look at the colors on the board, look at the images on the novelties, and the custom alpha set (if you so choose) and piece it all together.