Tab-less browsing might seem tricky but it is actually 3 times more productive when done right!

Open new stacks from the plus (➕) icon on the SpaceBar.
In stacks, open the cards that you want to have together.
Scroll through open cards within a stack instead of switching.
Jump from stack to stack with keyboard shortcuts by pressing ⌘ (or ctrl on Windows) and stack number keys simultaneously. ⌘+1, ⌘+2 (ctrl+1, ctrl+2)

Stack