Order of displaying information

Is there a golden rule to go by when deciding the order in which users are going to see the content?

I made a mockup in which I compare two cases. The first one is the one I'd like to apply. The second one is the generic Facebook/Instagram post.

The way I see, on FB/ig (case 2) the first thing a user will see when scrolling is the author of the post, followed by the actual post (whether it is a video/picture/text) then followed by icons (like, share etc.) and on the last row the description of the post. A tl;dr would be, see the author, see the content, decide what to do with that (comment, like, share) and at the end read something about it. Seems like a natural flow.

In my case (case 1), the aforementioned 'natural flow' is disrupted as I serve the content (whether it is going to be a picture, video or wall of text) first, followed by profile/user and icons (on the same row). On the last row I'd like to place the description.

I don't have arguments to back my changes more than I am not into the way Facebook and Instagram looks like. I cannot ignore the fact that they (most likely) invested a ton into research on how to serve content.

In the end, this kind of dilemma is going to be solved with AB testing but I wanted some other opinions.