One of the things I often hear from couples is "well, there is a venue coordinator, so we don't need a planner". I'm here to break down the difference for you between venue coordinators and event planners. Because, that is the first thing you should know...there is a difference. The second thing is that those venue coordinators, they will still tell you that you need a planner!
First of all, all the mad props and love to my venue coordinators, catering directors and on-site managers friends out there! These are highly skilled people who do an amazing job at their job and you need them. They know everything there is to know about their venue. They know it's quirks and how it is best set up and how it flows best when things are done a certain way. It is their domain and that should be respected!
However, while these same people very well may be seasoned event planners, it is not actually their job to create a timeline for you and your other vendors. They very likely have preferred vendors or even vendors they know and love to work with. It is not their job to negotiate contracts with those vendors on your behalf. They are not going to go to the florist with you, they are not going to deliver your cards and gifts back to your hotel room at the end of the night.
Of course they have the skills to do these things, but the fact of the matter is that it isn't actually their job. Not only that, it makes their job much easier when they do have a planner on site to place the escort cards and personal items, etc.
Don't cheat yourself out of the help you need during your big day because you think you already have it when you don't. On-site coordinators are amazing at what they do, but you still need a planner to fill the gaps for what they do not do! Make sure you are covered. Hire a planner!