2003 post season stats
Timlin 8 games, 9.2 ip, 1 hit, 11k/2bb (one intentional). 0RA 0.00 era. .310 WHIP
Williamson 8 games, 8.0ip, 3 hits, 14k/3bb. 1RA/1er 1.13 era. .750 WHIP
Embree 8 games, 6.2ip, 4 hits, 1k/0bb. 0 RA, 0.00 era, .600 WHIP.
Combined 24 games, 24.1ip, 8 hits, 26k/5bb. 1 RA/1er. 0.37 era, .534 WHIP.
Arroyo 3 games, 3.1 ip, 2 hits, 5k/2bb. 1RA/1er, 2.70 era, 1.200 WHIP. All against the Yankees.
I think his main argument has some merit regarding the 2019 club if you change it to "consistently reliable bullpen arm." Barnes has had stretches of dominance and stretches of meh. Of course, that's the case with a lot of bullpen arms.