Here's the long answer, I'll address combat first - the average combat knife is a 4" folder, with composite grips, that locks, and was likely purchased in the PX. I've carried Randalls, Gerbers, Beckers, Benchmades, probably a dozen others in the fixed blade category, they are share some disadvantages. First - the average soldier doesn't use them very often. The Army doesn't even teach knife combatives unless the bayonet is locked on the end of the rifle. Second, because they aren't used, they become dead weight. A long fixed blade takes up valuable real estate on field gear and weight in the load out. Non functional weight is something the soldier pares to the bone - he carries far too much as it is, and another half pound here, another half pound there adds up quickly.
Soldiers have been doing that long before the Civil War, when it became documented in photography. New soldiers getting their pictures taken held large Bowie knives. Old soldiers on the march carried a much smaller clasp knife they could use to eat with, or for chores. The Bowies were traded off or sent home.
Survival knives are another thing all together. If anything, the ones most heavily promoted in the past were based on military designs which centered on highly trained aviators being able to use them in escape and evasion. That is exactly what the average human who needs a knife doesn't need. The primary tasks in survival skills are actually the same as primitive living skills - preparing food, and woodcrafts. America was largely explored and traversed with 4-6" flat ground, plain handled knives, and in larger expeditions, carried by the dozens. Most were English made imports, and resembled the simple kitchen butcher knives we call them today.
In survival training, emphasis is placed on the same skills, and the knife is called on to be a bit more robust to prevent failure. Carrying dozens becomes redundant, again, weight is a factor. There are weight limit in flying, vehicle transportation, or on foot. So, one well made knife has become the standard - something the average human cannot break, even when abusing it, and which can resist damage and wear for long periods of time.
Casting aside another five paragraphs of material selection - just get a 4 to 6" flat ground blade, maybe a drop point, made from a simple steel like 1095. Exotic alloys aren't necessary or desirable. Unbreakable grips that are reliably fastened to form the handle are best, from a material that doesn't absorb water or noxious fluids. Definitely not paracord. Micarta or G10 is superior. Coat, plate, or treat the blade to prevent rust, and fashion a high quality sheath with reliable belt attachment.
In the current market, if it has the same specs and style as the ESEE series, it will do. If not, there should be some reason for the difference. No sawbacks, hollow handles, or compasses should be integrated, because in a survival situation, you need full sized ones that do the job properly.
It's that simple.
