I was just adding to what I think a professional drafter/designer needs to know to succeed, depending on the size and type of company you work for.
Maybe the "most drafting positions" got me.. I guess I mean the level of what you need to know depends on what you're drawing.
I work with structural engineers, I am not one. I can create a whole set of drawings with little to no input from them, but when it comes to actually sizing beams/columns and rebar size and spacing (etc), they need to provide me that. I know how the thing is going to get built and what gets field/shop designed and what we are responsible for etc.
So yes to do well as a drafter/designer, you need to know what you drawing/designing and how it's made/built.
I haven't worked out in the field as a steel fabricator/erector or foundation contractor, but have been around it long enough to know how it's done.