A fixed blade knife is more durable but in my 27 years of hunting I have never need anything bigger then a 4" folding hunter. I have been lost in the woods over night and did just fine with a folding knife. I am not a survival expert of any kind I am just speaking from experience.
When I head into the woods to hunt,camp,or fish I carry more then one knife all the time. I carry a strong folding saw,a small fixed knife with a 2" blade( skinner type) and a 4" folding hunter. I never had a need for a big rambo type knife.
When surviving, if possible you want two different knives. One should be a machete-like tool to handle larger jobs, and the other should be a smaller knife for general purposes. Also try to have at least one of those partially serrated (my opinion is if its on the smaller knife make sure its not serrated on the back of the blade as in survival you will probably need to but pressure on the knife by pushing on the back.) Field& Stream recommends the Tops/Buck Csar-T Liner-lock Folder as the best new survival knife.
Surefire also makes a knife called the Crank. It's not exactly a multi tool but it has a bottle opener, a 1/2 inch wrench, you can also insert a coin near the bottom to become a screwdrivers, it has a cord cutter and has frame holes so you can tie it to a stick or pole to make a spear.
I cant really gove you an answer,but what I can give you is a way to a solution, that is you have to find the anglde that you relate to or peaks your interest. A good paper is one that people get drawn into because it reaches them ln some way.As for me WW11 to me, I think of the holocaust and the effect it had on the survivors, their families and those who stood by and did nothing until it was too late.