None of these have been used in battle. But some have been used to hack up horse carcasses. And all have seen some general field use, yard work, camp chores, etc.
The Gransfors Bruks 'Forest Axe' is by far the best workhorse of the group. Whilst the smaller knife (Fallkniven A1) is barely a chopper at all, and whilst it could be pressed into service for multiple roles, it's best feature is that it is compact with a 6.3" long blade.
That leaves us with the 9" blade of a Swamp Rat 'Battle Rat' knife; a Gransfors Bruks 'Wildlife' Hatchet; and that giant tomahawk thingy that I had custom made by the guy who started Ranger Knives back before it was a mass manufactured brand.
Guess which one doesn't ever go anywhere with me. That 'hawk is huge, heavy, and poorly balanced. The hatchet is the best chopper of the three by far because not only does it cut well, but it's not too heavy to repeat that action dozens of times. And it will certainly cut through bone better than the large knife. The knife would be great for a place that has coconuts and bamboo, but could be and has been pressed into service for chopping and batoning wood in the rocky mountains. It's just not ideal.
Small to medium sized fixed blades (4-6") are very useful. For any task a knife that size won't handle easily, it's straight to a hatchet or axe for me. More steel isn't always the answer. The right steel in the right place is far better. Between the small hatchet and the larger axe, I have another which is a Goldilocks size when trying to find a balance between function and portability. It can still be swung with one hand, of with two if you want to get some weight behind your swing. Length is about 19" and it's designed to chop stuff, not to look cool. But trust me when I say, it would spilt skulls if called upon to do so.
Basically, I think sharpened prybars (large knives) have limited utility and only excel at splitting long pieces of wood via batoning, as a shovel when you didn't bring one, or as a makeshift paddle for a canoe. And I think tomahawks are not made for working. As I plan on using a chopping tool for work far more than as a weapon, they seem pretty silly to me. Just my two cents.