@Iltasyuko
As others have noted, the empty Stryker XL on frame can be a little disconcerting. When I first got mine I was concerned and wondered if I made the right decision. But once your bag is loaded it’s less of an issue. The compression straps take up most slack.
I got the Styker XL as my daypack to allow me to pack quarters right away vs. head back to camp for a pack frame.
Note the pack isn’t very large. It’s fine a majority of the time, but when temps dip it suddenly fills instantly. That’s probably why Kifaru released the Hellbender…slightly more pack room. The Hellbender wasn’t available when I got my Styker XL. I’d probably go Hellbender if I did it again…maybe. I do like the full Cordura of the Styker XL and actually use the PALS webbing in my Styker sling, something I have come to appreciate for having portable waders, water filter, etc. in pockets without disturbing the main bag of day gear.
I’ve used the Styker XL for full camp with a separate bag in the sling. It’s very convenient to drop the bag and not repack day gear. I’ve since switched to the Fulcrum for my backpack hunts. It’s a fantastic bag which serves two purposes (full camp + day mode) extremely well! Plus it keeps your load where it should be vs. pushed out away from your back on the frame.
In my case I also almost always have a Sherman pocket attached when using my Stryker XL. That pocket run to the frame tab loops takes away the slop you’re rightfully concerned about. Some extra straps and/or K-clips will further eat up that slack.
Overall don’t worry about it. When you get loaded and cinched down it’s a nonissue. Again my comments are about the Styker XL; I have no personal experience with the Hellbender.