A long time ago, I had a band that had 10 people in it.
Sax, Trombone, Trumpet, Bass, Guitar, Drums, Keys (B3) and 3 singers(did splits etc. on stage). We did various R&B cover songs, and the group was tight.
There was a lot to think about to get all of the group together. We had no mics except for the singers.
How big is your band?