I don't think this is quite true about either group but it's dangerously close if you know what I mean. How & why genesis specifically shares so much content with other stories from the region is an extremely interesting subject in itself and still under active developing scholarship but I'm not qualified represent it well.
That's definitely a misunderstanding of the roman pantheon though. It was already a fully formed syncretic religion at the time of acculturation of the greek gods into it, having regularly adapted to & adopted nearby belief systems as it encountered them.
Some of the greek gods were fully syncretized with similar-enough roman gods, some only partially, some greek gods were adopted more completely because there was no near enough equivalent, and then some roman gods continued in more or less their previous form, for example janus who the greeks had nothing comparable to. But even a lot of the pre-greek exposure "roman" gods were themselves adopted from other cultures, and/or already syncretized with indigenous ones. In any case it wasn't "mostly" stolen from any one place, it followed a pretty typical pattern for syncretic religions. The acceptance & merging of the greek gods was only one event in what was at the time already a venerable and dynamic religious system.
You also need to be careful about timelines. The greek cultural influence here is at like 800bc, predating the roman republic much less the empire. It arguably predates anything you could reasonably call rome at all, this is in the distant past that was already mythological to the roman republic. This was always part of their cultural essentially.
Some of the parallels between the Roman and Greek pantheons are also because they derive from the common Indo-European root. e.g. Jupiter, Zeus pater and Dyaus pitr being the sky father
Mark S Smith has written pretty persuasively about history of the Jews as El worshipers. See eg Abdeel, Abiel, Adbeel, Amiel, Ariel, Azarel, Azareel, Aziel, Asael, Ashbel, Adael, etc. Yet the paucity of yhwh names. Not to mention, the Bible flat out states as much “I am the LORD. I appeared to Abraham, to Isaac, and to Jacob, as God Almighty (El Shaddai), but by my name the LORD (YHWH) I did not make myself known to them.”
Many of the biblical names ending in "ah" are YHWH names. This includes many of the prophets. So Elijah, Zechariah, Jeremiah, Micaiah, Isaiah, for instance are all "ah" ending names that have a meaning related to YHWH in the same way that the "el" ending names are related to El. And then Joshua (and, hence, Jesus) is also a YHWH name.
That's definitely a misunderstanding of the roman pantheon though. It was already a fully formed syncretic religion at the time of acculturation of the greek gods into it, having regularly adapted to & adopted nearby belief systems as it encountered them.
Some of the greek gods were fully syncretized with similar-enough roman gods, some only partially, some greek gods were adopted more completely because there was no near enough equivalent, and then some roman gods continued in more or less their previous form, for example janus who the greeks had nothing comparable to. But even a lot of the pre-greek exposure "roman" gods were themselves adopted from other cultures, and/or already syncretized with indigenous ones. In any case it wasn't "mostly" stolen from any one place, it followed a pretty typical pattern for syncretic religions. The acceptance & merging of the greek gods was only one event in what was at the time already a venerable and dynamic religious system.
You also need to be careful about timelines. The greek cultural influence here is at like 800bc, predating the roman republic much less the empire. It arguably predates anything you could reasonably call rome at all, this is in the distant past that was already mythological to the roman republic. This was always part of their cultural essentially.