Torque (in ft-lbs) is what you are after, not force (in pounds). Most any full grown male in the US can put 70 pounds of lateral force on a blade. Torque is the amount of force (lets say 70 pounds) times the length of the lever. In this case, the lever is a knife with about (in Ed's case) a 5 inch blade. Let's make some assumtions, since I've never actually seen one of Ed's knives in person. First, lets say that about 1 inch of blade is in a stump you want to pry apart, to get some dry wood for a fire (it's hypothetical, I know there are better ways). Now, let's assume the handle of Ed's knife is about 5 inches long. I don't really know about you or Ed's knives, but for me, this length provides a versatile and comfy handle. Now lets assume the effort you put into prying is concetrated on the center of the handle, 2.5 inches from the end. In reality, it will be distributed over however much of the handle you are gripping, but again, this is an example. We have a knife with an overall length of about 10 inches (5" blade + 5" handle). We lose one inch due to it being embedded in the stump, so we're down to 9" now. Your efforts are concentrated on a point 2.5 inches from the end of the handle, so 9 - 2.5 is a 6.5" lever. If you can get the leverage right, I have no doubt a grown man can put over 100 pound of force on the handle, and some will be able to get over 150, maybe 200 pounds. I've seen individuals put over 250 ft-lbs of torque on a bolt with a wrench about 14 inches long. That works out to nearly 215 pounds of force on the end of the wrench. These were strong iron workers, so lets assume you can get 150 pounds on the handle of the knife, unless you're exceptionally strong. Now we have 6.5 inches divided by 12 inches/foot, for a lever length of 0.54 feet. 0.54 feet times 150 pounds is over 80 ft-lbs (81.2). Longer knives give you longer levers, with the same amount of force, so you can get much higher torques. IMO, for a battle blade, you need to be able to resist considerably more than 70 ft-lbs, given that battle blades tend to have longer blades, ranging from 7" (USMC Kabar) to 9" plus (Busse Battel Mistress, BK9, Trailmaster, Loredo, etc.). This assumes you intend to use the knife for purposes that need lateral strength, such as prying open crates, etc. If not, get as much as you think you'll need. Sorry for the math. If I assume you can do it and you can't or won't, then you have no idea what I said. If I assume you can't and you can, some people get insulted. I may be done for either way.
PS: I always get sent to the quick reply window, but this is not what I'd consider a quick reply.
