some intereting stuff to be considered:
-Spears can contribute to make the gameplay more versatile because they are weapons with longer reach than any other weapons except ranged. Spears add a huge element to combat. You have a weapon which can be held one or two handed, and also thrown. It has the longest attacking distance of any melee weapon. It does primarily thrust damage, as opposed to axes, maces, and swords which are mixes of chop/crush/thrust.
They are fragile. So you can't just keep everything at bay forever, your spear will break. Also, you can't throw spears at everything because they weigh about 100x as much as an arrow, ie only 1 or 2 if you're using it as a missile weapon.
-Spears were historically used to hunt mammoths it should be logical that in a province were such animals exist, such historical fact would exist too.