I agree that science can't be bound by the rigid structures of most applied disciplines, and that the freedom to combine technologies in novel ways is a pre-requisite to novel findings.
What I find objectionable is the inability of scientists to explicitly delegate tasks to domain specialists in their everyday work when it makes sense. I think that it's unrealistic of you to believe that engineers always work with "a fully dimensioned and toleranced drawing" before starting work on a project and that your would work "grind to a halt". Indeed, there's a reason for the qualifier rapid in the term "rapid prototyping". If you can give an engineer general specifications for what you want and then leave him/her alone, he/she should be able to produce something that mostly fits your needs while avoiding all of the pitfalls that wouldn't have occurred to you. It would also be incorrect to assume that engineering does not involve creativity and is purely bound by rigid processes- if your requirements were strange enough, something fresh would inevitably be built.
This sort of delegation of course, is actually more efficient, since you can work on other tasks in parallel with the engineer (such as writing your next grant proposal or article or gasp teaching). Most scientists also already do this implicitly by choosing to purchase instrumentation from manufacturers like Olympus, Phillips, or Siemens rather than building it themselves.
Part of the reason for why I have such strong opinions about this matter, is that I've actually witnessed scientists waste more time messing around in fields where they were clearly out of their depth. As an example, there was a thread on a listserv in my (former) field that lasted for literally months that was solely devoted to the appearance of a website. Everyone wanted to turn the website design into an academic debate, when the website's creation (which had little to do with the substance of the scholarship itself) could have been turned over to a seasoned web developer and finished in less than a week or two.