Sheet metal tab and slot design - struggle

[GroMark]

Well, on second thought, I’d use a clamp, like the one in the image. I don’t know if this is an option for you, but it seems like the most secure solution. You‘d have to place them,with some specific spacing, but that would be it. If this is for e g transporting something or flow liquids /which mean you can’t disrupt the flat surface of the „floor“ sheet, you could nest the clamps in like in the second surface. Although, it might be that I’m overcomplicating things.