I don't think you understand very well how hardware design works. Most hardware designers write code just like software developers. Most of them have never used a hot air gun, and most of them can't explain in much detail how a transistor works at the physical level (they learned this once in their education, but have since forgotten, simply because they don't need to know this in their daytime jobs). Yes, once you need to fab your design (and iterate on it) you need other disciplines, but the work here is more or less the same for any design.