Right now, the only way to give users the ability to Sponsor or Advertise a group game is to grant them the permission Create and edit group games. The problem with this is that it also allows users to create but also edit your existing games.
This is a problem for any developer seeking funds to launch their game as they have to trust the user who will be Sponsoring or Advertising to not steal any of their games which has a high possibility to happen.
Roblox has no obligation to remove any “clones” of your game as you technically gave them the permission to view, edit or change your games.
This is why I believe there should be an extra permission similar to Advertise the group but instead it would be Advertise or Sponsor Group Games so that group owners can safely get their games Advertised / Sponsored by other users without risk of their game being stolen.