Got one word for you....Voicing.
Think of it like a layer cake.... depending on your 'ingredients' the more you have, the less densely you have to play...
Melody instrument (sax, trumpet, lead guitar, organ, RH, extra synth) to do fills and such....'icing on the cake' (not too much of that, think of an over-decorated wedding cake)
Choir/solo - call/ response. This can take up a lot of musical acreage, and is usally most important in a church setting, so if you play for these vocals you'll have to simplify.
Organ/piano RH - more chords, probably inverted or open voicing (split the chord up w/LH).
Try not to be in the same octave as the other keyboard player. You can trade on lead/echo lines and solos.
Organ/piano LH/ rhythm guitar - harmony. These should agree, or at least not 'clash' with each other.
If you want to do a Am7 chord, just tell the guitarist to do a C6 (they're the same chord, LOL)
If your guitarist can do higher jazz voicings, that's good.
Bass on the bottom. If you have a bass player do chords with your LH, let them do the bass lines, they'll appreciate it.
Otherwise you and the organ player can fight it out.
Drums to support it all...