No, Microsoft Office ISO/MSI (Non C2R) updates are not cumulative. There were some Microsoft Updatepacks like SP1 oder SP2, and sometimes there is a new single Hotfix to replace two old Hotfixes, but you have to install all Hotfixes. You can download and collect all updates and put these files in folder \Updates in the ISO. Nice tool for that: WHDownloader https://forums.mydigitallife.net/threads/whdownloader-support-and-chat.44645/