I have a love/hate relationship with sumac(especially staghorn, but the others are similar). It is an awesome plant to have around for thermal cover in the summer, deer will loaf in and around them and benefit from the shade they provide and breezes can still move air under the top growth. In winter, they are about as worthless as one could get. Once the leaves have dropped, you might as well have nothing but t-posts sticking out of the ground in that area. They will shade out most ground cover once they get thick and reach about 6'-8' tall. Summertime deer still love them at that stage, but in winter they are pretty worthless.