a/b
I forgot to note your allusion to African nascent democracies tending to dictatorship. That, I suggest, is not a counterpoint to monarchies tending towards tyranny, unless one means democratic monarchies tending towards tyranny; and that is hopefully excluded by my insistence that democratic monarchies are on the democratic side of my/our? scale. 

Your African example is simply a switch in mode of governance from one pole to the other, and the reverse switch is obviously also possible. The issue re tendency to tyranny only concerns the monarchy/dictatorship pole; and whether a case can be made for labelling that pole tyrannical. It might be wise for me to take back that notion, which in context I made as a concession to you.

In fact, democracy can also be tyrannical, specifically, the tyranny of a majority over a minority. Again, the problem is my lack of specificity. For me, every STABLE democracy involves iron clad protection of minorities.