First of all, needing to go down to 200 IP over the last 3 years combined, just to get a sample size of 150 SP'ers (5 teams x 5 in the rotation,) should tell you something about the state of innings eaters in MLB.
Let's see where Pivetta places out of the top 150 SP'ers by IP:
42 GS at 49 (more than most #2 SP'ers)
45 IP at 421 (middle of road 2nd starter amount)
77th fWAR at 4.7 (about like a middle of the road 3rd starter)
90 xFIP at 4.17 (worst 3rd SP'er in MLB- better than all 4th and 5th SP'ers.)
120 in ERA at 4.58 (worst 4th SP)
105 in ERA- at 105 (middle of the road 4th SP)
73 in SIERA at 4.08 (middle 3rd SP)
107 WHIP at 1.32 (middle 4th SP)
67 K-BB% at 16% (near top 3rd SP)
I'm not seeing a SP'er not worthy of a rotation slot, until we add 4 SP'ers with Bello. Sure, if Sale is healthy... Sure, if Houck can learn to go more than 4-5 IP.... Sure, if Crawford can prove 2023 was not a fluke and improve on his 4.51 ERA as a SP, including 5.40 over his last 6 starts....
Look, I hate building rotations from the 5 slot, but right now, I think he looks more likely to give us 28 GS, 160+ IP and an ERA around .425 or better than anyone else on the team, other than Bello. He's really our #2, right now. I'd like to make him share the number 5 slot with Sale, and I get grief.