CTS10228 is at least 2000 years old, and probably existed throughout a vast area because of Dacians/ Thracians. Dacian tribes were pushed probably even more to the Nord because of the expansion of the Roman Empire (after the fall of Decebalus, the Dacian King). I-Y3548 (age: 1458ybp) could be attributed to the White Croatians. Was the I-Y3548 mutation later on possible, because of the earlier movement of the Dacian Tribes to the North? Maybe... unfortunately we can only assume or presume... no scientific evidence yet...
A lot of people want that I-CTS10228 carriers are Thracian origin, but in reality this assumption cannot be supported.
About 1000 BC and earlier I-CTS10228 carriers were in the north of Europe, most probably in the Baltic region of today's Germany, it is time before than they arrived in upper Vistula region and surrounding.
They were Mesolithic survivors, whose ancestors long time ago were much more widespread in Europe, but unfortunately they had bottleneck.
Irony of destiny, it is possible R1a tribes pushed them to the south, it means in that time they were antagonists.
Gubin culture of Jastorf group probably were culture of these people, I1 carriers had influx and probably Germanic language is result of these impact.
And Croats are far from these areas, Croatian scientists highlight that Croat is Iranian name and original Croats were Iranian, some other scientists claim some other origin (Turkish, Bulgarian etc.) but it doesn't matter areas of original Croats are very very far from areas where I-CTS10228 lived and moved.
So, I-CTS10228 carriers were not Thracian, Illyiran, Slavic, Iranian Croat etc.
I-CTS10228 carriers were European Mesolithic survivors and they became Germanized due to impact of I1 carriers.
Bastarnae were the most likely bearers these genetics (and maybe to a lesser extent Scirii), only later when they moved from the Vistula river to the east they came in contact and mixed with Dacians/Thracins (they first entered in Balkans 179 BC) and Sarmatians, and centuries after that, after Zarubintsy culture, their descendants participated in Kiev culture and ethnogenesis of Slavs.