Fair enough. I certainly see where you're coming from.
I personally find it hard to believe Epicurus and his school really thought that the sun was about the size of a football when he wrote it "may be a little larger or a little smaller, or precisely as great as it is seen to be." They could see the sun set behind the hills or fall over the horizon where they had seen ships pass into the distance. The sun "as it is seen to be" is larger than one of those ships of it's in the distance or larger than the hill it is passing behind. That's why Gellar-Goad's article at least made me take a second look at what those texts could be saying. The school said to trust the senses, and my senses would tell me the sun is bigger than a hill or boat at least. The moon obscures the sun during an eclipse, and the moon is bigger than the hills too. Or maybe I'm biased by the modern knowledge I can't unknow?
That said, I certainly don't discount the possibility that they could have just got it wrong.