He was right.
Rui walked into missions knowing that his Martial Art would allow him to overcome hurdles and obstacles that ordinary humans couldn't even dream of doing so. Although he was conscious enough to know that his combat prowess did not have any direct role in this mission asides from being taken more seriously, it was not easy to alter his subconscious attitude.
Still, Rui's attitude was driven by his conscious thought, since he put a lot of thought into each and every one of his decisions when completing missions, so this wasn't too much of a problem.
"One of the biggest issues with the previous Martial Artists who had been appointed as the diplomat was that they were largely unable to shake the subconscious attitude that physical power was the answer to all missions, in a way. Or at least necessary for all missions," He sighed. "In this mission, any displays of your combat prowess will only reduce the chances of success of your mission."