Hi Chillau,
If you want to design a project only for landscape view for tablet and Desktop; A suggestion would be to increase the width for Tablet view in captivate from '768' to something which represents the max landscape width of the device. For example,setting the tablet view width as 1024 px and desktop as 1280 px, will make sure that you see same view when you switch between the portrait and landscape view on your tablet.(Considering that the tablet landscape width is 1024px or below).
You mentioned that "Tablet view appears to be wrong when the project is published from Moodle and viewed on devices". Can you explain more about the issues which you are facing? It will be better if you can share a sample project. My email id is aren@adobe.com