You can use harder woods if you laminate them. If your glue joints are "bad", you should sand the pieces longer/flatter or use a different glue if it's a color thing. My first osage bow was from a thin stave. I glued a scrap piece from the stave to build the handle. After several pop offs, I ended up splitting the handle piece piggy back style and glued a couple lams in between and one on the non-rest side. Haven't had an issue since.