I understand the archaeology doesn't allow a high resolution picture, but there are some things that you can't dismiss. Things like copper coming from the Balkans, and contemporaneous Dnieper-Donets and Samara layers possessing very similar material culture.
I don't disagree necessarily with a pre-farming-PIE in Samara, but it has no real linguistic definition. Also, Yamnaya has no Anatolian farmer, and yet you require the farming lexicon to come from mixing with the Balkans. It also sounds like you would need to see this in the genetics. This is problematic.
And I don't think we can say the the "main lexicon" is pastoral.
Many of their agricultural terms are borrowed from the Middle East languages. These words like the type of activity were alien to them and obviously borrowed from outside.
L. Zaliznyak: (although there are some controversial terms, such as borrowing a horse, as for me)
The well-known linguist V. Illich-Svitych (1964) noted that a certain part of the agrarian and cattle-breeding vocabulary was borrowed from the prasemites and Sumerians. As an example of prasemitic borrowings, the researcher named the words: tauro - bull, gait - goat, agno - lamb, bar - grain, cereals, dehno - bread, grain, kern - millstone, medu - honey, sweet, sekur - ax, nahu - vessel , ship, haster - star, septm - seven, klau - key, etc. According to V. Illich-Svitych, from the language of Sumerians, u borrowed the words: kou - cow, reud - ore, auesk - gold, akro - field, duer - doors, hkor - mountains, etc. (Gamkrelidze, Ivanov, 1984, pp. 272-276).
However, especially a lot of agricultural and livestock terminology, names of food products, household items and-e borrowed from the Prahattans and the Prakhurites, whose ancestral home is localized in Anatolia and in the upper reaches of the Tigris and the Euphrates. SA Starostin (1988, pp. 112-163) believes that the roots of klau, medu, akgho, bar and some others are not Primamitic or Sumerian, but Hatto-Khuritic ones, cited by V. Illich-Svitych. In addition, he suggests numerous examples of Hutto-Khuritic vocabulary in i-e languages. Here are just some of them: ekuo - horse, kago - goat, porko - pig, hvelena - wave, ouig - oats, hag - berry, rughio - rye, lino - lion, kulo - count, list, gueran - millstone, sel - village, dholo - valley, arho - open space, area, tuer - cottage cheese, sur - cheese, bhar - barley, penkue - five and many others. An analysis of these linguistic borrowings shows that they occurred in the process of direct contacts of the Pra-Indo-Europeans with the more developed Prahutto-Khurites not later than the V millennium BC. (Starostin, 1988, pp. 112-113, 152-154).
By the time this coincides with the contacts Eneolithic Dereivka culture with Tripolye.
And this why agrarian cultures, including Anatolia, hardly can be considered as IE. Because many agricultural terms for In PIE have non Indo-European roots.
A main lexicon IE can be even north-Mesolithic. All this flora and fauna (elks and birches), as well as the names of different tools.
And Samara and Dnepro-Donets are similar, why not. All these cultures have common Mesolithic roots.