A wedding planning and a venue coordinator are two different roles. While it is true that a venue coordinator and wedding planner will have some cross over, there is still a huge added value to having both, so that you have two professionals working together.
A wedding planner is your go-to person for every detail of your wedding day and resolves issues that fall outside of the venue. This includes elements such as budget, wedding stationery, hair and make-up arrangements, flowers, decorations/props, wedding cake, transport, guest list management, seating plan and so on. The venue coordinator is responsible for issues relating to the venue specifically. For example, ensuring that the venue bar is fully stocked, and staff are briefed about when the reception drinks are to be served to guests.