Additional starters double as additional relievers, especially now that Taillon is gone. All of the SPs we have that tou might give some side-eye to either have explicit success in the pen or at minimum have a times through the order penalty which makes you think they'd play up in shorter bursts.
The team is *probably* fine to add one SP. Shota and Boyd are good, the SP they add will probably be good, and Cabrera will probably come back fine. Outside shot Brown has enough time to make it back as a SP too. But like we saw last year Boyd and Shota limped to the finish line performance-wise and Horton got hurt basically the last possible moment and suddenly we get caught with our pants down.
Add two starters and you insulate yourselves that much more. I'm not as flippant as most about burning through the farm, but like this pitching staff's going to be on shakey ground even if they go add one very good SP.