Buddha's direct disciples I know of and some major Theravadin figures in the 19-20th centuries, but that leaves a vast period of time I am ignorant of. Aside from Buddhagosha and Ashoka there must have been many Arahants or sages that Theravadins admire.
So please give us some short bios here or references to books about sages from the Southern tradition between, say, 300 bce and 1800.
A bodhisattva does not become weary of evil beings nor does he commit the error of bringing forth thoughts inclined to reject them and cast them aside. Avatamsaka Sutra, ch. 25