Hi Jackie,
The chicken definitely will not take as much time as the butt, but it will take less wood. If you use the typical 5-6oz of wood for the butt, you will over smoke the chicken. If you use, 2oz for the chicken, then you will not have as much smoke flavour for the butt.
I would start with 5-6 oz for the butt and only put the butt in first, then after about 60-90 minutes later, add the chicken. At that point if you notice that there is not enough smoke, just add a slight bit more to the smoker box, but not too much.
It's a bit tricky when smoking two difference sizes do meat at the same time that would typically used different amounts of wood and cooking times. Good luck and let's us know how it works out for you.