Multi Column Layout in Admin

[cancan101]

What is the recommend way to achieve a multi column layout in the admin bundle? I am open to either a responsive (e.g. flex box) and non responsive (fixed number of columns). For example I have 4 components that I want to show 2 across:

or perhaps to reflow based on screen width.

I can accomplish the fixed width using a "Field Container" per row. Is that the best way to accomplish this? There is not much documentation on "Field Containers" ("Fieldsets").