reuse of Google Service account advisable?

Hey Gang! I belong to an organization in which I was one of two developers building apps. The other guy has successfully deployed an app via play.google.com, and when I explore the site for our shared Google Developer account I can see a history of his releases, and also find a Google Play store page for his latest.

He has moved on, no longer available. In the meantime, I’m getting ready to deploy my app in a similar way and working my way thru Submit to app stores - Expo Documentation. Where I’m getting hung up is with Google Service account, for which I will need it seems a serviceAccountKeyPath/private key as part of my build submission process.

Is it sensible that for our organization, that there would be a service account created for each app? Or is it rather more likely to use the same service account key for all of our Google Play Store apps?

Is there a chance I can somehow access our existing service account credentials via our shared Google Developer account, or perhaps through expo somehow? Or is this reasonable, or should I instead just make my own google service account?

Thank you