How lightweight do you want to go? You CAN survive naked with a sharp rock, but do you really want to?
When I was a Soldier I carried alot of combat gear, and believe me, every pound counts.
I understand that every pound counts. For me, being prepared for survival doesn't include hundreds of rounds of ammo, so I have way more wiggle room than a soldier in many regards. As does pretty much everyone here. I just need to keep myself in one piece, warm/dry, hydrated/fed and either lay low or get back to town. I make a general effort to keep what I carry around 50 pounds maximum; shaving 4 or 8 ounces here or there isn't going to make a difference. In a pair of boots, heck yeah. But not on my belt or in my pack. If you're talking long-term survival, well, then I'd add more weight not less.
The poster did say SURVIVAL right? So what would you rather have, a 16oz knife and 8oz less emergency water or an 8oz knife and 8oz of extra water? Let's be serious.
I'm completely serious. Are you? Where I wander, a 2-oz bottle of iodine tabs will get me all the safe water I could ask for*. How long is that "extra" glass of water going to last you? There, I just saved you 6 ounces

Plus, it's pretty rare to just scavenge-up a blade that will do what I want it to. I'd rather carry the tabs, 32 ounces of fresh water or Gatorade and a 16-ounce knife, is that an option? Allow me that, and the stuff I EDC anyway and I could likely keep myself together just fine.
Blood grooves are dumb. Where'd you read that? A Sgt. Rock comic book?
I'm not raggin' on anyone else's way of doing things, but the whole lightweight thing can quickly turn into a fetish that's just plain silly. On the other hand, I don't roam around with a felling axe, either.
BTW I'm no Paul Bunyan, I'm only 6'4"
* I should note, in central/northern WI you're seldom more than MAYBE an hour's walk from clear water, and if you can't find shelter/fire material you're just not looking. If I was in different terrain I'd probably have different priorities.