There is a summoning doll skill you can learn to increase their range.
Even maxing Wisdom, you will not get enough experience to gain an extra level by the end of the main game, but will level slightly faster. Each character would have to learn the skill to get the benefit. Since you can unlearn skills and gold shouldn't be a problem, learning Wisdom is more beneficial than leaving a large number of spare skill points until you decide where to put them.
