Really depends on the number of satellites, the target orbit(s), the payload/application, link strategy, the risk profile that you're willing to accept, etc.
There are quite a few constellations that you can benchmark by: - Astrocast (IoT) [1] - Fleet (IoT) [2] - Iceye (Earth Obs) [3] - Planet (Earth Obs) [4] - Spire (Earth Obs, Navigation) [5] - Capella Space (Earth Obs) [6]
And many more ...