Updated and Corrected verison², accounting for (a good amount of) misidentified and contaminated samples.
Its not looking good for Yamnayabros... Only 7.7% of Corded Ware samples carry Yamnaya Lineages.
The picture isn't much better when using the R1b-dominated Bell Beakers, who have even less (7.2%) Yamnaya Lineages.

Using a clade depth of 9, which is about equal to TMRCA of ~3000-3300bc for R1b.