The band I play bass in is a bit like that, the guitarist/singer put it together and he does all the songwriting/organising/etc.
I mostly get to do my own thing as regards bass parts, and am quite happy to let someone else make all the decisions as regards where we play, what the setlist is, etc.
The way I look at it, he has an idea of what he wants to do with the band, whereas I'm just happy to play music, so it suits me fine.
At the last count, we have had (IIRC) 23 different people contribute at various gigs, in part due to band members having other bands/commitments which get in the way rather than people hired and fired, though one or two have only done one gig