Maybe $14M/1 for Flaherty or $15M/2 for Fedde are too expensive to call depth signings, but neither was a huge long term risk.
Here might be some that fit the bill:
Gibson 131 IP 4.26 ERA ($13M/1, maybe too pricey, as well)
Severino 134 IP 4.17 ERA ($13M/1)
Lynn 106 IP 4.06 ERA ($11M/1)
Lorenzen 113 IP 3.73 ERA ($4.5M/1)
It's interesting to note than maybe the best SP depth signing for uner $4M, last winter was Cooper Criswell at $1M (63 IP 4.02 ERA and a 1.1 fWAR. That 1.1 fWAR is tied for 88th best in MLB among all pitchers and tied with Severino, Lynn, Bello and others. It's better than Montas, Cole Irvin, Detmers, Flexen, Scherzer, Cole, Luzardo, Monty, Paxton and many others.
Maybe, this area was not as bad as we think. After all, we have used 9 SP'ers, this year, not counting openers:
24 Houck
24 Crawford
22 Bello
19 Pivetta
13 Criswell
6 Wink
4 Whitlock
3 Paxton
1 Anderson
We lost Gio, Whitlock and Murphy as options to start.
Other teams, like the Astros, have lost as many or more, so this is not an excuse, but Brez did have 9 options for 5 slots, and Criswell did okay.
What hurt, a lot was counting on Bello to do at least as well as 2023, but he did not. Houck and Crawford have done better than expected, despite recent woes. Pivetta has done about as expected. Wink was in the dog house for a while and has done about as expected. Paxton and Anderson failed.