Nice to meet you too Mr. Peter!
Sorry, dear compatriot, but your example is not relevant with the conversation for the Aristotelian term on "modesty". And when we try to confuse the study of Philosophy - giving examples - with political ideologies the result is always a mess. Plato did that in Syracuse as he had the desire to make in practice his philosophy and tried to educate "a wise King Philosopher". As it is very known he had failed three times on this, and in the end he has been sold as a slave !!! Poor Plato!
Moreover, those people that have the irresistible desire to make a career in politics in 99,999% are idealists - platonists - stoics as they also speaking to the people with empty words without meaning (see kenes doxes).
You said: "They (in the golden Dawn) were so highly popular for a time that nobody in Greece doubts that they could have climbed to stellar political heights".
I answer to your argument and on that failed example of yours :
Nobody have doubted... EXCEPT THE EPICUREANS, since they smell the platonists/stoics like the dog smells a hidden bone. HA !
So, my "modest" - friendly exhortation to you is that if you want to study properly the epicurean philosophy you have to clear your mind from political ideologies that always confuse the reality with the worlds that do not exist.
Finally, Epicurus says something remarkable to us in the following PD7. Thus, and in this PD we realize that Epicurus does not speak for "modesty", but he speaks just for "safety".
Doctrine 7. Some men wished to become famous and conspicuous, thinking that they would thus win for themselves safety from other men. Wherefore if the life of such men is safe, they have obtained the good which nature craves; but if it is not safe, they do not possess that for which they strove at first by the instinct of (their) nature.