I-A2512 formed 2300 ybp. The other 3 branches of I-Y3120 including I-Y3120* are mostly people in Eastern Europe - showing Slavic origins.
I-A2512 has 2 sub-branches. I-Y32624 so far has people of Greek origin (it also has a Mexican who has origins from 16nth century Greece) and a Chuvashian sample who could possible have an old Greek-Pontic origin. I-A10959 has people with origins in Southern Greece and about 1800 years ago the group split with the formation of I-Y23115 subgroup which consists of Askenazi Jewish population from Eastern Europe.
I-A2512* sample (I-Y32624 - and I-A10959-) which belongs to my dad's sample is from Thasos island, Greece. Perhaps someone moved to the Balkans from the north around 2200 years ago (maybe Bastarnae, Macedonia's allies at that time) and from then on subbranches were formed in Southern Greece. Byzantine empire did have a small Jewish minority so possibly someone who lived there later moved in Eastern Europe. In my opinion I-A2512 is the only non Slavic branch of I-Y3120 since it's the only one that spread in the Balkans (and Greeks only) before AD times. The more samples we have the easier it will be to form an accurate opinion. After all I-A2512 was found 2-3 years ago.