or are you referring to the manager here are the marketing manager
Obviously, signature campaign is a form of marketing, calling it as a marketing manager is the same for campaign manager, people are just used to call the latter.
While it's not necessary to hire such manager since anyone here can handle/manage a campaign, but dont expect you will get the same results. If op is too busy handling other matter outside of this forum then hiring one is a huge help, but to make sure money should be considered.
I am not a casino owner - I am a social media manager and many people come to get their business promoted on different forums like youtube, tiktok, fb and instagram.
So its a good option to work in your domain and let the marketing person take care of marketing work.