Hiya Chris,
I was thinking more along the lines of general principles rather than specific crossroads, although the southern end of the moor was mined so would have carried traffic onto the moor. These open moors get quite a lot of snow in wintertime so the tracks to the workings would have needed marking.
The other thing to consider is that, in my opinion, these routes seem fairly isolated now but have been major routes between the Vale of Pickering and the northern moors since prehistory and only fell into obscurity during the later half of the second millenium.
The reason why I originally posted these stones, apart from their general quirkyness and ability to inspire debate, was that I believe that the stones may have originally been erected to mark a trackway that dates to way back when. The prehistoric trackways of the NYM tend to stick to the higher ground and follow the riggs.
If the stones were recent e.g seventeenth or eighteenth century, I would expect them to be dressed stones or at least of a uniform size and nature.
It's odd that the stone that most folk feel to be 'authentic'- the southerly stone, strikes me as an obvious route marker. as it is situated on the brow of a steep hill and above a ford. If you are travelling from Pickering to the Upper Esk valley it is an invaluable landmark.
That's my ten bobs worth matey, all said and done it's a crackin' part of the world.