If they understand how it works well enough to go through a code review and modify it based on that code review, what's the problem? That just... sounds like what your work is going to be.
Good question. Like I said elsewhere in this thread, there are many people who are knowledgeable and intelligent about coding, but cannot code. They are different skills. I've met many people like this.
I could study Romeo+Juliet and know everything about it that lit professors know. But I could never write it.
For another example, from my time at Boeing, the engineers were divided into two independent groups. One group designed, the other group analyzed and checked the designs. They were different skills, and the engineers would gravitate to whichever path best suited them.
