No it makes it harder and more of a pain. Trust me I have a friend who loves breaking into my personal server. That one trick two ssh running on different ports screwed with him for a long, long time. He is a genius of a hacker and has been doing it for a living for years. When he finally got in he was so pissed that threw him.
You are describing an anecdotal instance of a person whose capabilities are not established being thrown by something that nmap will catch on a normal scan.
Color me skeptical. I shall decline to "trust you."
Not my competence it his competence I trust and I got him good with that one since it never occurred to him that one stupid trick messed with him for so long. Lie 5 minutes a month.
