I fall into that category. My hair is fine, and not very porous. I was confused when people talked about "great slip", because everything with an ounce of conditioning in it gives me good slip, and this might explain why. I can even brush it dry, if I'm careful - there aren't too many knots on any given day.
My hair does also weigh down easily with product. If I use too much KCCC
(thanks, kathymack - I'm hooked!) it can be greasy and stringy. Thinking about it, I can say that BRHG left me greasy and was too heavy. Same with GDLI to some extent. But all of the things in my sig have been fine. Maybe I've just been lucky in choosing products that are lighter, so far? I'm fairly new at this.
There are probably more, subtle factors here but I can see how curlies with low porosity and fine hair might find things in common.