AFAIK, there's no strict percentage. One of the reasons I like paleo so much is I don't have to focus on macronutrient ratios, just on eating actual real quality food within certain confines.
Personally I don't pay a whole let of attention to the macros either. However, I am still working on finding the right rough boundaries where I both feel satiated and I am getting leaner. At present, I more regularly lose weight when I eat more protein, but this doesn't always make me feel full. Fat, on the other hand, is great for feeling full and maintaining weight.
It depends on gut bacteria, metabolism, and a host of other factors. If you notice that you feel better one way or the other, go with that. Also bear in mind that HG tribes didn't necessarily eat the same ratios consistently, depending on what was caught/found/in season.
I like Dr. Harris on questions of this sort: