Mining

It makes little sense to study archery, you think. The nomadic tribes nearby do not concern you, really, and you don't plan to launch an offensive against them. Pottery, though useful, is not of immediate importance.

That left mining, which, in your estimation, is crucial if your village is to advance. As of now, you and your people have been using rudimentary tool which you discovered scattered around the area before founding your village. However, if you planned to create more advanced equipment, then mining (and forging) would be a must.

While your polymath goes off to teach the mining skill to your workers, your partner tells you that she thinks you should send a scouting team to look for new plots of land to till. The scouts will likely be gone for a week or two, and so, you will not need to send them with much food. On the other hand, any food that leaves with the scouts means less food for your people, and if the scouts return without having found any new soil to till, then their efforts (not to mention the food they consumed) would have been wasted.