I think a lot depends on the outfitter. Most drop camps are set up to take 4 to 6 hunters and if you do not fill the camp with your buddies, you could have strangers there with you. Most drop camps are set up for the season and are not moved, so again depending on when you hunt, there could have been hunters there before you. Ask the outfitter lots of questions.
I have lots of experience with spot camps, which is where a packer or outfitter takes you (and all the gear) to a predetermined spot and leaves you. They will them pick you up on a predetermined date. This is done a lot in Calif in the Sierras. Advantage is that your group are the only ones there (at least by the outfitter), disadvantage is you should know the area so you get a decent area to hunt.