some considerations and more R modelling:
Yamnaya developed from Khvalynsk (southern Russia) and Sredny Stog (eastern Ukraine).
Sredny Stog are the people that domesticated the horse. Yamnaya was transmitted this, so they were among first populations to be able to cover larger distances shorter.
Khvalynsk was much more EHG (Eastern Hunter Gatherer) than Sredny Stog (the latter had contacts with neighbour farmer culture of Tripolie):
RUS_Khvalynsk_En
RUS_Sidelkino_HG,85.3
Kura-Araxes_ARM_Kaps,7.9
IRN_Ganj_Dareh_N,6.8
UKR_Sredny_Stog_II_En
RUS_Sidelkino_HG,51
Kura-Araxes_ARM_Kaps,27.1
Anatolia_Barcin_N,21.9
Yamnaya seems to have developed more from Khvalynsk while Corded and Beakers more from Sredny Stog, and notice that Mediterranean Beakers were largely of Neolithic farmer stock:
Yamnaya_RUS_Samara
RUS_Khvalynsk_En,65.1
Kura-Araxes_ARM_Kaps,20.4
UKR_Sredny_Stog_II_En,10.5
IRN_Ganj_Dareh_N,4
Yamnaya_UKR
RUS_Khvalynsk_En,53.8
UKR_Sredny_Stog_II_En,24.6
Kura-Araxes_ARM_Kaps,13.5
IRN_Ganj_Dareh_N,8.1
Yamnaya_BGR
UKR_Sredny_Stog_II_En,49.9
Kura-Araxes_ARM_Kaps,27.7
Anatolia_Barcin_N,9.4
WHG,7.3
RUS_Khvalynsk_En,4.8
Nganassan,0.9
Corded_Ware_Baltic
UKR_Sredny_Stog_II_En,49.7
RUS_Khvalynsk_En,23.1
WHG,13.1
Anatolia_Barcin_N,8.8
Kura-Araxes_ARM_Kaps,5.3
Corded_Ware_CZE
UKR_Sredny_Stog_II_En,69.9
RUS_Khvalynsk_En,11.9
Kura-Araxes_ARM_Kaps,9.1
WHG,6.6
Anatolia_Barcin_N,2.5
Bell_Beaker_Rhine-Main
UKR_Sredny_Stog_II_En,54.1
RUS_Khvalynsk_En,17.4
Anatolia_Barcin_N,11.2
WHG,8.5
Kura-Araxes_ARM_Kaps,6.8
Han,1.3
IRN_Shahr_I_Sokhta_BA3,0.7
Bell_Beaker_Scotland
UKR_Sredny_Stog_II_En,82.4
WHG,10.1
Anatolia_Barcin_N,7.5
(RUS_Khvalynsk_En,0)
Bell_Beaker_Iberia
Anatolia_Barcin_N,66.4
WHG,23.8
UKR_Sredny_Stog_II_En,9.8
(RUS_Khvalynsk_En,0)
Bell_Beaker_ITA
Anatolia_Barcin_N,65.5
UKR_Sredny_Stog_II_En,23.3
WHG,11.2
(RUS_Khvalynsk_En,0)

