I don't think I ever watched a race that Liggett and Sherwin commentated on that included Indurain. I only have watched classics during that era. So maybe they were boring during the Tour idk.They tried to enthuse about Indurain whereas what was in Duffield's baguette and how it came to be there was often more interesting than the racing.
And I had access to ES at the very end of Duffield's career. At the time, I thought maybe he was just horrible due to old age. But, nope, when I watch older races he was just as bad. I can kind of see how Kirby is similar except Kirby can actually be funny. All of the most horrible ES commentators over the years (e.g., Quigley, Harmon) seemed to inherit different horrible traits from Duffield.