1 Hjalmar Schacht 143
2 Arthur Seyss-Inquart 141
3 Hermann Goering 138
4 Karl Doenitz 138
5 Franz von Papen 134
6 Eric Raeder 134
7 Dr. Hans Frank 130
8 Hans Fritsche 130
9 Baldur von Schirach 130
10 Joachim von Ribbentrop 129
https://en.wikipedia.org/wiki/Nuremberg_trials#Intelligence_...
Which perhaps is still remarkable, but I think it is a much higher frequency than most people would intuit from the number.
Tyrants know this. You see it when they feel threatened and start purging their subordinates. If they don't respect you they can fear you instead.
1: http://shakespeare.mit.edu/julius_caesar/julius_caesar.1.2.h...
There's also the question of whether or not the genetic changes they attempt to make would increase intelligence independently of openness, which is likely possible, but that would require a deeper understanding and familiarity with the subject.