I'll take this in another direction.....
....even in the instances where you may not have the luxury of band rehearsals or don't have the time to form that solid cohesiveness, a band can still kill if the band members follow some basic guidelines and common courtesies to playing in a group.
The main thing is simply everyone needs to LISTEN. A few examples...
The bass player and the drummer's kick drum can't be fighting over the rhythm. They should be together and bouncing/grooving on the same beat almost all the time.
The keyboard player or organist, when playing with a bass player, doesn't need to run the bass with their left hand (or foot pedals), that makes for conflicting sounds with all those "lows" going on. Not to mention, it gives the bass player a little more freedom to do his/her thang!
Another thing is situational awareness. The drummer can't be showin' ALL his licks in one song.....the bass player can't be poppin/slappin to "I Surrender All". Everyone needs to know whats going on, that they aren't a bunch of individuals putting on a bunch of individual concerts at the same time, but rather band that should be working together, EACH responsible for providing their specific musical element, so that it will ultimately end up as one sound, glorifying God.
Of course the band rehearsals and cohesiveness will help to glue all of that together. But on top of that, the individual mindset of each band member should be about the "group" as opposed to on them trying to shine. That being done on an individual level, in and of itself will exponentially increase the effectiveness of any band rehearsal and worship experience.
Tj
