I think it is incredible such obsolete information is still spread as if it is current. The Bell Beakers are a 3rd mil BC offshoot of the westernmost tip of Corded Ware area, the Netherlands. Thus, there is not any controversy or contradiction. The physical BB type closely resemble the Dutch phenotype. The Bell Beakers did not only spread to the east - where indeed they met some Kurgan culture in the Aunjetitz Complex. They also spread to England, Ireland, Portugal, Italy. There is a strong case for assuming Celtic (or even Celto-Italic?) local continuity without any later migrations. So, having this clear, why not assume the intrusion of Indo European language in the same area where East and West met, this same Aunjetitz Complex, but instead having influences going east?