There are several ways to consider this answer.
A more scientific and historical account may be that the stories of Giants in the land are mutations of the original encounters between Neanderthal and early Cro-Magnon. Certainly the Neanderthals were stronger, bulkier, and (possibly) larger in stature than the Cro-Magnons. It may also have been slight mutations in genetics, as (at least in the Biblical accounts) the Giants/Nephilim/Anakim were all of one race/tribe/culture/what-have-you. Of course, anything higher than about 5 feet would have been a giant to them.*
On a more mythological standpoint, the figures of giants/large monsters as adversaries to the prominent mythic race is hardly unique. Think of the Titans, the Jotnar, the Formorii, the Rakshas, Tiamat's brood... All they really are are figures of the uncontrollable nature surrounding human culture, the forces that must be bargained with, defeated or appeased to ensure survival.
On an angelic/scriptural account, supposedly the Grigori are responsible the Nephilim. As I understand it, when the Grigori attempted to rectify Lucifer's "mistake," a fringe group decided to create their own "mankind" in response to Alaha's "precious Adam." It was mostly Sariel's and Shemhazai's doing.
So, my answer is: Yes <!-- s

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*No, Goliath was
not 9'9". That's a misconception based on an untranslatable measurement and differences in biological anatomy throughout the years. He was probably no taller than about 6'0-6'5.