I personally think they are too small for K&C. While the ED HT is closer to 1/29 and therefore slightly larger than the FL halftrack, it is still too small for my Thomas Gunn figures. All of these are packed away right now, so it would be hard to get pictures, unfortunately.
For me, the FL and ED halftracks are close enough that they can be displayed together. It is only when you put them side by side that the differences are that noticeable. Also, since they have different body styles (C versus D), it also hides some of the variation.