@DMehaffy thanks for your response !
@soupette Indeed, dynamic zone can do the tricks in terms of layout. That’s what I’m using right now and it’s working wonderfully. 
However, let’s say you have a list of projects (so documents in a collection) and you want to rearrange the order of the projects, this is - almost - not possible.
You can do it if you add a new integer field like order or something… but that’s mean you have to manually re-order every project… if you have more than 50 projects, it becomes very chronophage and unmaintainable.
I think this feature request could be high priority and game changer, in my opinion. I see a lot of comments for other headless CMS about the lack of this feature.