Skill weighting determines what skill weight a weapon uses to deal damage with, it has quite a large effect. Default is 50. The number tells you how much the fighting/hunting skill is used compared to the strength skill. Taking extreme cases the crossbow has 80 and the claymore has 30. This means that the crossbow is a much better choice for someone who is good at fighting/hunting but not so strong, reversely it means that the claymore is good for someone who is strong, but not very good at fighting/hunting. If the skills are somewhat equal it doesn't really matter what weapon you choose right then, but depending on what environment you're in it will later. If you are in an area with a lot of animal types and you hunt daily, both strength and hunting will rise a level each in two decades. If you mostly train on people it will be slower, unless you exhaust yourself by hitting 5-6 people each time but then you can't do much else so that's not practical. Plus you'd be vulnerable to attack and dragging.