This is why I like to build loops tailored for my team and always buy loops where I can access the stems as opposed to a mixed split track!
I think its important loops supplement our band instead of replacing an existing member. I also change whats in a loop depending on what I have as a band. I would rather approach a song with the band I have and think about what would work with that band, then use a loop adjusted/custom made to supplement that, as opposed to If i have no e gtr and drums just use recorded versions of them and do a song as if I had a full band.
An example would be we have a fair few piano players at church, but not necessary keys players (they don't tend to venture into pads, synths, strings etc and stick with a piano sound). I'm not going to tell them they have to buy a big complicated keyboard and learn all of that (it would be good!) but I'd rather supplement the band with those pads and synths etc from a loop which are parts not previously being done. Some piano bits might sneak in there as well, but i'd try and make them different from what the live player would do and sound different as well (maybe a really reverbed and spaced out sound, or in reverse etc)
I try and make an mp3 split track of the loop available to the band in dropbox a week before the rehearsal, so they can listen to the loop and practise with it and adjust their parts if necessary. Also it gives other members of the band a chance to suggest tweaks etc.