Not really Frein, Logs are over abundant, consider that at most you need 1 Lumber while you need 2 - 3 Ingots, and the ratio from log -> lumber is 1 : 1, ore -> ingot is 3 : 1 or 8 : 3. There are very few recipes that utilise 2 lumbers, most of the Bows use 2 branches along with lumber instead.