DC, you raise some very good questions in your post about my "one of each" collection.
Some of them have their very own thread, because the answers are as varied as the number of modelers here on the forum, but, mostly because someone asked and started a thread.
I will hit the highlights here, starting with the units. Since I am doing "one of each Squadron" as my largest theme, I will talk about that. Then the choices in the smaller steps along the way will be common sense as to why I choose those steps.
In building one of each Navy Squadron, you run into areas where you will do a lot of research because no one has ever done decals in 1/72 scale for that squadron. (in some cases, no one has ever done decals in ANY scale) There are two solutions to doing something like a VA-16 Skyraider for the "16 slot" in the collection. One would be to bug a known 1/72 decal vendor to do it up on a sheet, and provide him with all the help he needs for references. I do that for some units, but, I also know how to make and print decals at home on my Laser Printer. So, since I like having a unique collection, I do some of those aircraft myself, which lets me have one of a kind models. Another factor is that in order to really do "one of each squadron" a person has to know the history of the many squadrons that disestablished or were renamed as the Navy went through the years. That means when I get the VF-11 F-4 Phantom and/or VF-11 F-8 Crusader built, I still have to build the F2H Banshee for the VF-11 that was disestablished before the "new" VF-11 got the Crusader. And I would still have to build a VF-43 aircraft from before they were redesignated into the "new" VF-11 while working up in their first batch of F-8s.
I wouldn't do one of every aircraft in a squadron, to me that hits right on that spot that people think of when they think of doing almost the same build over and over again.
To me, doing Skyhawks From VA-12, VA-15, VA-22, VA-23, VA-34, VA-36, VSF-1, VSF-3, VA-43, VA-44, VA-45, VA-46, up to VA-216, is "different enough", because if I choose to hit each different variant of Scooter as I go, and the variations in the Insignia and paint regs as I go, there is enough difference in the markings to have a variety on the shelves. Those gaps in my numbers above are filled by VF units operating Phantoms, Demons, Crusaders, etc. And it would be very hard for anyone that knows the least bit about Navair to confuse a VA-23 Black Knight's "Bar Sinister" markings with the "Supersonic Red Bird" of the VA-94 Mighty Shrikes. Heck, the FSM Navair modelers can spot the difference between VA-23 Black Knights from "my" Black Knights from across the room. (VMFA-314)
So, just from VF-11 to VA-16, there could/should be the following
VF-11 Banshee
VF-11 Crusader or Phantom or both (different VF-11) (or VFA-11 Super Hornet)
VA-12 Skyhawk or Corsair II or both
VF-13 Skyray, Cougar, or Crusader or all three
VF-14 Demon, Phantom, Tomcat, or VFA-14 Super Hornet
VA-15 Skyraider, Skyhawk, or Corsair II, or all three, because all three were really different units
VA-16 Skyraider
As you can see, that shelf would be all different aircraft, or all different markings for whenever you see two of the same aircraft.
So, if you look only at that Skyhawk stash pic I posted, and don't realize that there in an F-4 Phantom section to the right of the Scooters, and then Intruder, Crusaders, Tomcat, Corsair, Skyraider, "Detatchment aircraft", Hornet, etc, and even Kfir and F-5s to the left, it can look like a lot "of the same model".
But, they will be unique,,,,,,,,,and at least 30 or more of those models will be very different than any other on the web, because I will have made my own markings for them using my book collection as the reference. About 200 of the finished models will be models that anyone could have done using off the shelf 1/72 decals.
To get some of the things you need to do more than 2 of any given aircraft type, you have four choices, buy two of some of the decal sheets, know in advance that you are going to only use one scheme from a sheet that includes two sets of overall markings, buy some of the "all Insignia" and "data for F-4" types of sheets, and work in as many kit decals as you have that are high enough quality. Some kit decals are higher quality than aftermarket sheets, or at least the same level.
Now you can see the obvious steps before a complete collection of each squadron would be first to get one of each Wing, then one from each Carrier. And Anne's least favorite part of this, after those steps are done, and I have one of each squadron done, there is always the possibility of filling in each Wing so that I have for example, AA-100, AA-200, AA-300 from the Forrestal. Not to mention that a unit's markings sometimes changed for each cruise, or for each sub type of aircraft they were assigned.
well, that is probably wordy enough for today
Rex
edit for a PS: And I "cut down" to the above collection, because, in my 50 years of modeling, I had already built "one of each of the Revell 1/72 kits", and one of each of the Airfix US kits, Each Monogram, etc, etc and started doing multiples with aftermarket decal sheets of some of those kits. So, I cut down my stash, and my library, paint colors, etc, etc,,,,,,,,,to save money and to focus my research needs to a smaller area,,,,,,,real Mil-Specs and physical TO's and other books are too expensive for me to have stayed as "branched out" in my subject matter as I was.