I'm not here to whine about the timber pile, I like that it takes 5 days, and 40 boards and that you might end up with mouldy boards, as sevenless said in the only thread I could find about timber piles, this is what gives things value.
All I am suggesting is that when you finishing collecting the board from a pile, the 10 rocks are scattered around and you can pick them up to use in the next pile, I don't see that it would cause any balance issues. And the code exists in the form of scattering wood blocks upon destroying a stump.