Simply looking at the dominant Y-DNA allready shows Yamna/CW/Bell Beaker are not the same, alltough this paper seems to suggest that the origins of CW and Bell Beaker are entangled.
Yet all 3 have the same autosomal component + some admixture with late European neolithic/chalcolithic.
This autosomal component was formed prior to the Yamna era, it was formed during late Khvalynsk.
It is very likely that the PIE lived between the Samara bend (EHG) and the northern Caucasus (CHG) at the time when the steppe DNA was formed.
R1a-M417 and R1b-M269 were amongst them.
I think there is no reason that they spoke PIE, b/c they lived in europe and have R1b/R1a.
People always think that Yangshao O3 people in yellow river spoke sino-tibetan like modern Han Chinese. However, tonal language like sino –tibetan appeared 5 century in china.
Marlory said that afanasievo culture could not be connected to tocharian. There is not any cereal sample in afanasivo grave, but farming words in tocharian language.
I think late PIE speaker the celts, the Myceneans and Vedic Aryan’s cultures cannot be explained without snake. However any snake artifact has not been found in yamna/ cwc/bb culture.
Sunhead means snake head. Snake is a sun’s ray, so thunderbolt. Braids in their heads are snakes. Snake is a circle, so celtic and vedic mandala. The snake concept is not DNA, but their soul:

https://www.suppressedhistories.net/...geometric.html