tree= 1 hit with stone axe=5 wood
1 hit with metal axe 10 wood
stone= 1 hit with stone axe = 4 stone
1 hit with metal pick 8 stone
metal= 1 hit with stone axe = 3
1 hit with metal pick = 6
sulfur= 1 hit with stone axe = 2
1 hit with metal pick = 4.
Of course, the tree/node would break down faster than the current one.