I still think there has to be a better method of measuring that. Some people are fast, sloppy writers, and others are slow and careful. I wouldn't say that fast and sloppy equals "brighter". DD is very fast with other fine motor skills, like making those rainbow loom things, weaving, braiding hair, playing piano, etc. Those are all things where the "slow processing" isn't apparent. Ask her what 9X6 + 8X7 is though and it will be more obvious. So there are big differences between motor speed with her depending on the task. Writing is really the only area where I see a deficit in terms of fine motor.
To be fair, fast and sloppy would be likely to be down-scored somewhat on Coding, too, since one does need to copy the symbols accurately enough to be recognizable.
Another note is that the fluent and dysfluent tasks that you mention are not really the same. The fluent tasks are largely repetitive patterns or sequential patterns, where there are contextual and meaningful threads to follow, once you get going, while multiplication facts involve retrieval fluency, often in a fairly scanty context.
But to your overall point, I would agree. It's just that there are tasks with decent correlations to intelligence, that we use as proxies for whatever direct measurement would be, which may not be good proxies for every person.
