Many kits are unsufficiently detailed and need to be supplemented with other parts picked elsewere. My favourite kits for that are tanks kits. They provide many varied parts for varied use. This technique is copied to the one the ILM model makers used in the 70’s and the 80’s during the Star Wars preproduction phase. For instance, the Boba Fett’s Slave One wings come from car doors of a Porsche and the wings of the Tie Bomber have been taken almost as they were in a Vader’s Tie X-1 kit produced just after A New hope.