Roboticst need RnD for basic functions of the job, like exosuit boards resrach, and positronic brain resarch, as well as cyborg upgrades and power cell upgrades for the cyborg, as well as autolathe for components. RnD is not much of a job position than a chore, but the one that are the most dependadnt on are the roboticist, not to mention, they are familiar with the equipment since half of RnD is alredy in the robotics lab. scientist can do anything they can without even touching rnd once, but roboticist need it for many of the things they would be able to do. If you don't have someone at RnD, you would ask cargo, where, for example, a xenoarcheologist can do his job even if he is the only crewmember on board.
RnD can be done in as little as 15 minutes, and there never be touched again, so it's not a core part of the scientist job as it is for the roboticist.