Andrew understandably wrote this book from the perspective of his Hero Duncan who was on the wrong side of History at that time. Uganda being a complex amalgamation of tribes and cultures enforced by the British as he acknowledged without any common denominator.
I wonder if he went back to Uganda today his other Hero Museveni would not fall into the same category of his predecessors (like son, like father) and he would want to write perhaps another appendix to his book or write another accurate one altogether.