The lack of pockets is exactly why I use them. I've had panniers with lots of pockets in the past and they were mostly useless. The pockets were usually too small or the wrong size to have much utility. I also long ago started packing my gear in plastic bags because old panniers were waterproof in theory only. Once I went to the Ortliebs, I just kept up the practice. My clothes are all packed in ziplock bags and placed in the Ortliebs in whatever manner I wish. Everything is easily accessible within the bag.

You can also get external pockets for the Ortiebs if you so wish. You could place them anywhere on the bag.