Actually, come to think of it, and purely as speculation, I would guess there would have been a couple of types, and these based on what the Egyptians were using (as there was probably a strong Egyptian influence due to the period of slavery in Egypt). I know it's based on a Wilbur Smith book (my theory), but he does do his research. There might've been composite recurve bows, which took quite some making, as well as simpler, lighter, but more easily-produced longbows.
But I'd love someone who actually knows more about this stuff to set me straight.