I had a look at Stone Age Man this week and unless you eliminate footholds out right, it definitely feels easier than f7A+ to come out the roof and then go up the hanging arete - that exit felt like f6C+ to me
I gave mantling onto the slab a go and it felt grotesque but I suspect cleaning the slab would reveal a few more semi-decent holds. The mantle the way I tried it felt hard (like f7A+/B) so I assume that is the actual crux of Stone Age Man.
This seems to match up with the NMC guidebook topo, but I don't know for certain.