I try to nail the bass part in the very beginning. Then we (drs, b) can give the base to the others, as we are 11 in my main band. From that point of view it looks like I have not very much space, but actually more time to fix the tinier details (tempo and agogic changes, accents, colouring notes...).
There's quite a lot of arranging within the band, and it is easier if the drummer and me can support arrangement work from the start. Besides many choices I do are subtle compared to winds (3) or singers (4) in the big picture. Not meaningless at all, but different.