There are other natural cordages besides nylon that would be more traditional. It's a good idea to have dynamic backing and cable backing of silk cords and flax cords have been used.
Also, 3 Rivers archery does sell some nice artificial sinew, just FYI. Real sinew at about 6 cords per animal does make it hard to come by(4 cords from legs and 2 from back). Thats when gut and rawhide are nice substitutes.