I noticed that there have not been any replies to this post - so I thought maybe I could contribute as an observer (not as a bride).
Many times I have seen multiple weddings conducted at once - especially at Dreams. I have never had a couple express anything negative regarding the other wedding. Usually the weddings are spread apart that they do not interfere with one another.
We have even had the brides get together and take pics at times... It's kind of fun!
So if you are worried that they will be on top of each other, put your mind at ease - these resorts are massive and, like I said, i have not ever seen a problem in the past.