Don't take the following as an insult, it's an honest question.
Ι don't understand what the big deal with E-V13 is. It's an irrelevant haplo in the grand scheme of things, outside of Greece and the Balkans, when it comes to historical events.
It's either R1b/R1a or Js that seem to signify cultural and linguistic shifts.
First off, your own haplogroup is never unimportant, because its your lineage which can be traced thousands of years.
Second, E-V13 was at one point much bigger than all of the Baltoslavic lineages taken together. So it was very important and widespread, contributed to major emerging Bronze Age (Urnfield) and Iron Age (Hallstatt) cultures directly and indirectly, representing some of the largest people in ancient history (Daco-Thracians).
E-V13 is still one of the major European haplogroups and its main branches E-Z5018 and E-Z5017 being among the top haplogroups in Europe with an ancestor in that time frame.
The latter being a fact because of the rapid growth it experienced in the LBA to the EIA. And such a rapid growth and founder event needs to be explained.
Similar founder and growth events for other haplogroups were clear from the onset, like
- R-Z2103 = Yamnaya
- R-U106 + I-M253 = Germanic
- R-Z282 = Corded Ware and Balto-Slavic
- J-L283 = Illyrian
- R-L51 = Bell Beakers, Tumulus culture and Celts
- R-Z93 = Indo-Iranians: Iranians, Scytho-Sarmatians, Indo-Aryans
- N-P43 = Uralic, Finno-Ugric
etc.
You see, all of the major haplogroups, some of which were or are much smaller than E-V13, have their ethnocultural wave origin. They all can be traced back to a specific region and ethnicity, by and large. And for all of them, at least one of the factors - region, culture, ethnicity, being known.
The big thing about E-V13 is exactly that: It is a big player, it was and still is important for the male demographic base in West Eurasians, but its ultimate origin and spread being still unexplained and unknown to larger degree than that of the other main haplogroups.
Once we find the Bronze origin and expansion of E-V13, presumably in Channelled Ware - or another group contributing to Stamped Pottery as the less likely option, much of the debate will be over and there won't be as much need to discuss known things.
Like who debates whether or not I-M253 was largely spread by Germanics? Now its just about when and where exactly, which tribe etc. But that the vast majority of modern I-M253 being carried and spread out by Germanics is now beyond doubt.
As long as we don't have glass clear and irrefutable evidence for the E-V13 expansion, the debate will go on.
We already have clear and irrefutable evidence for E-V13 being Daco-Thracian, but some people refuse to accept it. And the question of how exactly E-V13 became the main lineage of the Daco-Thracians is still unresolved, we just have better and worse theories, we need more data to be sure.
In this respect E-V13 is similar to I-M253 and J-L283, because we know with which people the latter spread, but not how exactly it got to dominate in the post-steppe environment.
