The usually have very light VTF. I'm actually considering some Soundsmith moving irons right now; but not the 28cu model (1g), rather the 23uc model (1.3g). My take is they are great trackers and provide lots of resolution due to maintaining better and intimate contact with the groove.
I would have thought the opposite; in a high compliance cartridge, the needle is freer to follow the grove without having to carry the cartridge body and tonearm with it. On the other hand, a low compliance cartridge would require that the cartridge body and tonearm more closely follow the motion of the needle.
That said, the question asked by the original poster is a good one and one that is probably best answered by an actual cartridge designer. I've often wondered what the relationship was between the output voltage level of a cartridge and audio fidelity (do low output cartridges offer better fidelity and why?). I don't know that one would want to answer such a question because it gets into design philosophies and the tradeoffs that are made in any cartridge design.