It is not necessary to know how a watch is designed or manufactured to tell time. All that is necessary is that one understands how to read numbers, or an 'operational' knowledge. Effective use of time is a concept even further removed from an engineering knowledge of watches.
The question was "Is it reasonable to assume that anyone with absolutely no engineering knowledge can ever be as safe a pilot as someone who has".
It is my opinion operational knowledge is necessary to operate a helicopter. Operational knowledge will of necessity include some engineering knowledge using either the Lappos motherland or new world definition. Safety is in part knowing why and how, but also how much, when, and should.
Will an engineering knowledge make one a safer pilot? Not necessarily. Will an engineering knowledge make a safe pilot safer? Probably.
If one were the to say in a word what the condition of being a safe pilot is, its basis lies first in seriously devoting one's body, mind and soul to the exercise of sound judgement and decision-making skills.