Opinions...much like the useful, yet stinky rectal opening are standard equipment on everyone. So, I am going to fart out a little wisdom of my own here.
I don't agree with the OP's assessment. Number one...where did the numbers come from to quantify or backup your statements? The truth is, I don't believe a prepared person's chances of survival can even be quantified.
Secondly...without specialized training for the entire "group", your ability to lead (assuming of course you posess the bility to do so) will be severely degraded because you will have a gaggle of amateurs who don't have the training and respect for chain of command to follow orders without bickering and argument and debate. Personally...I have neither the time or patience to try to imbibe new and critical skills into a gaggle of amateurs.
If you want to claim the mantle of "Leader", "Grand Poobah", "Head Of The Fraternal Order Of Water Buffalo" or whatever...where did YOU obtain your specialized skills that would qualify YOU as a leader and (GOD I HATE THIS WORD) "tactical specialist"?
On my own hook...I'd have a MUCH better chance of surviving long term without the encumberance of a gaggle of others looking to me to keep them alive, and I haven't the patience to argue with ANYONE when it comes to doing what I say when I say it. My debate would most probably end for someone with a round through the brain pan if their BS was degrading the chances for my family unit to make it through.
I don't want to have to teach anyone how to clear a building. I did it for more years than I can count when I was an officer. SWAT, gangs-narcotics, and felony apprehension squad....THAT qualifies ME to do those things. Eben my wife who is a currently serving officer doesn't have that training, but I would certainly trust her to have my back because she HAS cleared buildings, and done the job in the real world for nearly 10 years. She hasn't learned all she knows about (we are going to do away with "tactics") techniques from the latest issue of MALL COP, or TACTICAL SPECTATOR.
A group of un-trained yahoos will make too much noise to "operate" successfully. the bellyaching, bitching, and all around lack of discipline will make them nothing more than targets. Training is a LOT more than buying the new and shiny tacticool gadget from www.iwannabehispeedlowdrag.com
. Training is a LOT more than shooting your bright shiny new M4 at the square range. Training, done right involves a lot of time, money, sweat, blood, and pain.
There are some former military who will claim tha mantle of leader. BUT...unless you were a marine 0311 or an Army 11B who actually had your ass in the grass and had at least made Squad Leader...you will be staring at SOMEONE hoping SOMEONE will give you an order and tell you what do do.
I grew up in the desert, and in the mountains here in Arizona, on a working horse ranch. I am very comfortable in those environments, and learned hunting, finding water, and making fire from my grandpa and great grandpa. I am the first to admit, I am NOT a combat veteran NCO who learned unit tactics in a forest or desert environment, but I KNOW those environments. What I DO know is unit operations in an urban environment, and have been on more dope house raids, and call outs than I care to remember. Yes, our goal WAS to secure the subject with no loss of life...but on more than one occaision it didn't work out that way. By the time I retired from SWAT, I had made entry team leader...so I know how hard it is to train men (women too) to be effective in that environment.
So, I would hypothesize that you have a much better chance of making it through with just your family if you have planned appropriately. Foster good relations with a VERY select few neighbors. Tell NO one else about your preps, and be ready to defend what you have until you are down to your last round.
But don't fall into an illusionary state thinking that you're going to be some kind of born again Rambo or Chuck Norris in the post apocalyptic world. If you are actually trying to LEARN something, and get real TRAINING...good for you, but be realistic. Your BEST chance will be staying in one place and defending that ONE place until you MUST move, and then your chances just dropped dramatically if you are a nomad. You will spend the vast majority of your time just trying not to get killed, let alone feeding yourself and your family.
If you happen to be a part of your "A Team"...how long is it going to be until the food runs short, and faced with individual survival, the team will fall apart, and someone will kill someone else for the last MRE or box of raisins?
There are a LOT of things that can go wrong with a single family SHTF scenario. Things can just flat go wrong. BUT...when you add a collection of egos, and testosterone filled tactical teddy wannabes...the chances for things to go wrong increases exponentially.
Personally...I give ME a lot better chance than US.