You can ship games without a graphics programmer pretty easily now-a-days because of all the engines. What you generally need a graphics programmer for are things like

1. optimization

   A graphics programmer would know and/or learn how a particular engine works and be able to direct the artists or modify the materials or merge models or use other techniques etc to get better performance from the engine.

2. understanding and instruction

   A artist wants to achieve a certain effect. The graphics programmer who understands how the engine works can explain how to achieve that effect.

3. customizations and effects

   Certain effects might require programming. Much of the rendering of [Bound](https://i.sstatic.net/apqQk.jpg) is custom.