You don't need anything complicated, but it is neat to find the C.G., because on oddly shaped wings, you may find the Center of Lift is further aft or forward than you thought. On Ekranoplans, the center of lift moves forward as the craft rises into ground effect, which is why they need to have a stabilator, or elevator, out of the turbulence and high in the clean airflow, so that control can be maintained. That is why all the Russian W.I.Gs have such big tail planes, and is also the key to making a successful
W.ing
i.n
G.round Effect aircraft.