So, it seems this group of surgeons were sitting about during an interlude, when the usual topic came up...
The first surgeon said:
"Accountants are the best to operate on because when you open them up, everything inside is numbered."
The second surgeon said:
"Nah, librarians are the best. Everything inside them is in alphabetical order."
The third pipes up:
"Try electricians! Everything inside THEM is color coded."
The fourth sneers:
"Lawyers. They're heartless, spineless, gutless and their heads and their butts are interchangeable."
To which the fifth surgeon, who has been quietly listening to the conversation while sipping from a bottle of Jack Daniels (as all surgeons do between operations), says:
"I like engineers... they always understand when you have a few parts left over at the end."