I have 2 loops, one for the sticky posts, and one for all the posts that are not sticky. I only display the latest 3 sticky posts. If there are more than 3 sticky posts, the older stickies are not displayed anywhere. (Not in the sticky loop because they aren’t the latest 3 stickies, and not in the default loop for the non-stickies because they are marked as sticky posts.)
Is there a possibility to prohibit the backend user to mark more than 3 posts as sticky posts at the same time? Or is there a possibility to tell the sticky posts except the latest 3 to be like “normal” posts?
You could do something like this in the theme where you would add the sticky posts displayed in the first loop to $do_not_duplicate in the first loop, then in the second loop query for all posts but check to make sure you are not putting those posts up again.