What could go wrong?
Just like any other engineering project, you assume many things could go wrong, and try to reduce risk while containing costs.
We presently have the luxury of debating about giving fire control to automated systems. That window will close, and soon.
Before long, near-peer battles on Earth or in space will simply happen at a pace beyond human capability to keep up and respond in a timely manner. This is because of directed-energy weapons which operate at speed-of-light, missiles and projectiles operating at miles-per-second speeds in space and upper atmosphere, and complex battlefield awareness networks with sensor fusion and supporting modeling and simulation. Meat brains just can't analyze rapidly-changing situations and respond in milliseconds, so we'll simply have no choice about automating battlespace analysis and at least some of the fire control. We know that's where we're going beyond all doubt, so we should determine to be first and best.