Meaningless comparison. If it weren't for the superficial similarity that both professions are used for rhetorical exaggeration purposes, this would be like asking, "are pianists better musicians than violinists?"

Surgeons of any sort rely primarily on highly developed and trained visual-tactile skills. A lot of their background knowledge, as with all doctors, relies on tons of memorization, case literature and hands on practice.

Rocket scientists (and engineers) are mostly applied mathematicians who work in their heads or on paper/computer for the most part, with much less memorization, almost no real-time pressures or demanding visual-tactile work. You could be paralyzed and still do good rocket science. Most time-critical or difficult hands-on stuff is the province of technicians, pilots and other kinds of specialists, except in rare crisis situations. Even experimentalists largely rely on others for hands on work.

So two very different kinds of thinking. Neurosurgeons are more like elite basketball players. Rocket scientists are for the most part "offline" thinkers who use different brain capabilities to a large extent.