Prevent a content user to edit and publish a scheduled layout

I have meet an issue as below:
Step 1: I create the first user, this user can only create, design, and publish layout.
Step 2: The second user (manager) can preview and schedule the layout for displays.
Step 3: When the layout is playing in the players, the first user can checkout and edit the layout and publish it again. This layout will change and apply immediately to players.
How to avoid Step 3? I don’t want the first user to have the right to change whatever is being shown without the second user’s permission.
Sorry for my bad English and thanks in advance!!!