Obviously we need more data from every region, but I am still not convinced by your argument. I don't see why only hallstatt clades would be spread by later groups and not any branches from their own time, probabilistically this doesn't click for me. These branches are confirmed for now, so they have to be explained properly.
I will write a new post/thread, because I have now a good explanation for the two wave TMRCA of E-V13.
The first being Gava/Chanelled Ware/Fluted Ware, that's practically proven at this point. The second comes from within this horizon, but it has a somewhat different distribution. Its basis are the Northern Thracians/Daco-Thracians, with first the Thraco-Cimmerian horizon, then Basarabi-Bosut and finally the Geto-Scythians. These three create, successively, networks which first create Hallstatt itself, then influence it big over time and finally even connecting the West and the East up to La Tene, by transmitting new cultural innovations. Part of it were the trousers, new cavalry tactics and the animal style. Basaraboid influences were widespread throughout Hungary, into Austria and the Czech Republic. In my opinion these migrations of individuals and small groups for the most part, used Hallstatt like a hub which spread it into the Celtic population.
There were later subclades spread too, but, and this is big, they usually went North to South. Its more likely they spread from Czechia, Poland, Slovakia, Austria, Ukraine, Romania to the Balkan, than vice versa. The primary exceptions are some Vlach groups, they are really the one big exception. But simply by looking their own frequency, and the subclades will prove it too, they can't explain the vast majority of the European distribution.
The crucial question is: Is there an overlap of the TMRCA between large regions and the answer is, mostly no. not after Hallstatt. Obviously subclades were mobile between ethnicities and regions, but they rarely jump over two to three such regions and ethnicities anywhere, that's really exceptional. But its absolutely not exceptional, E-V13 was even more mobile than many other haplogroups, in the typical expansion timings: 1.300-900 BC and 800-400 BC and the reason is clearly Channelled Ware and Hallstatt.
Even for the Balkan itself it might be provable: There were before the Romans, Germanics and Slavs two major expansion waves: One with the LBA-EIA transition/Channelled Ware, the second in Hallstatt with Basarabi. Basarabi split, especially its elite, in major branches in different directions, like North, West, East and South. We have so far no later overlap and while it surely will appear, it won't explain a lot. The vast majority of the modern distribution, unless its Greek colonisation, Germanics and Slavs, can be attributed to this two groups, Gava and Basarabi. Pșenicevo is part of the same complex for example, a descendent of Gava and contributor to Basarabi
. 
