Y DNA found in post-Urartian period. 600BC - 500AD.
The sample size is small for an accurate picture but it gives an idea what changed in this period compared to the preceding one. J2 increases. R1a appears. R1b and I2 decreases. J1 is Z1842 so it can be from the previous period. Genome wide they are similar to modern Armenians
One of L1a2 is in the 3300 year old branch. https://www.yfull.com/tree/L-Y11220/ So its an Iron Age expansion.
There is a modern Armenian and a Georgian who are close to the ancient L1a2 found in Beniamin. There is little doubt that those modern people are related to that ancient person. Where it formed and to what historic event it can be related is unknown. It could have formed somewhere near Kura river. In this case the presence in Chechens is explained. Another possibility is that it came from North Zagros/Mesopotamia. In this case the presence in Arabs is explained. But it's probable that it has a local origin related to Urartu/Biainili.
The other L1a2 from Karmir Blur is in a different branch that is not found yet in modern Armenians.
It's close to another ancient sample from Iron Age Hasanlu tepe in NW Iran. So there is little doubt that this case of L1a2 has a southern origin in RoA. It can be connected to the increase of Iranian influence in post-Urartian period. Although genome wide there is no evidence of increase of Iran_Neo. Which means that those new haplogroups didn't have a strong demographic impact, which is also visible in their rarity in modern Armenians.
We need much more aDNA from post-Urartian period especially between 600BC-200BC. My feeling is that the theory of Yervanduni (Orontid) dinasty from a region near Musasir in the most southern parts of historic Armenia ( North Zagros ) will find a genetic support. It must be noted that Khorenatsi reports not only Yervand but also Zarehians , Vahunis and others who appear in that period. So its possible we see the apparition of those clans which are not attested in the Urartian period