Well, I don't see any reason we cant just understand the text to be describing literal mountain sized giants. Wasn't it Og, the other giant of the Bible that had Extrabiblical literature in which he picked up a literal mountain, and threw it at an enemy army?
from wiki:
The Jewish Talmud embellishes the story, stating that Og was so large that he sought the destruction of the Israelites by uprooting a mountain so large, that it would have crushed the entire Israelite encampment. The Lord caused a swarm of ants to dig away the center of the mountain, which was resting on Og's head. The mountain then fell onto Og's shoulders. As Og attempted to lift the mountain off himself, the Lord caused Og's teeth to lengthen outward, becoming embedded into the mountain that was now surrounding his head. Moses, fulfilling
Yahweh's injunction not to fear him, seized a stick of ten cubits length, and jumped a similar vertical distance, succeeding in striking Og in the ankle. Og fell down and died upon hitting the ground.
[10] Many great rabbis, notably
Shlomo ibn Aderet, have explained this story in an allegorical manner.[
citation needed]