Too many cooks in the kitchen...
As a coordinator it can be difficult when you have a venue that has it's own coordinator, that is if that person wants to be the one in control of everything at their venue. It's understandable that they feel this way or that the venue will have them in place for a reason, but it does present issues when they sign off on a cake delivery, tell a staff member to lead the baker to the kitchen to put the cake in the cooler until the florist arrives, then forget where the cake is.
The florist called frantic because she couldn't find anyone who knew where the cake was and she wasn't supposed to set up the cake, just decorate it with the flowers. After several rounds of back and forth calls to the baker and the venue we finally found the cake, had someone at the venue place it on the table (it was already assembled in the cooler), and the florist was able to do her job.
The issues observed here are the reasons that every bride should have a coordinator. What bride wants to deal with this kind of stress while she is getting ready to walk down the aisle? None that I know of and none of the brides I work for have to, thankfully!