My take is that Kavanaugh’s part was the only area to focus on (Didn't like that but...) their part to go on the offensive.
Since NONE of the witnesses vouched for Ford, Repubs decided to play it safe. If Ford had a witness testifying who was “there”, Repubs would have probably grilled them both.
I wish they picked Judge Judy as the Interviewer.
She is a Democrat after all.