The cases you're looking at are 8cm taller and 8cm longer than these. And my right side case is 5cm thinner to fit beside the muffler and still have the same outside width.
But the pic shows: clothes, shoes, and clothes (I was visiting and helping, not going camping). Usually this side has a single bag of clothes and the front bag would be stove, food, and cook gear.
The opposite side is the wider case and carries tent, poles, pegs, s-bag and has room for more.
You'll note that S.Spiff and I both use stuff sacks instead of liners. I have liners but they bulge and sag and get pinched while closing the lid. Properly-sized stuff sacks stay in place, stay out of the way, and let me grab just what I'm looking for.
It also depends on how many cold-weather layers you take and the bulk of your tent and s.bag. (You can see a bit of a top case in this pic and it's very handy for shedding layers.)