Another silly mind view is of little bitty engagement rings being crushed by the products advertising they use diamonds.
Regarding your question. I do not recollect ever seeing a comparison between various forms of WS2. It has always been between WS2 and some form of oil. That makes the results spectacular; particularly if you have figured out how to make commercial quantities of IF WS2. Nor have I seen good information of the "effectiveness" of the Fullerenes structure delaminating vs other surface bonding approaches.
The following is purely my thinking on the subject. I have never seen corroborating data.
One thing I have thought would improve the results of the IF is the resultant size of material. The Bucky balls seem to run about 60nm. Now comes the guessing/assumptions. When a 60nm BB (see your mind image might have more validity than you thought) breaks up it seems to do so in layers. It does not really "peel" the onion. I suspect the forces necessary to cause this onion slicing is less that to remove a smaller piece (mill off) of a monolithic form. Now, if the diameter of the entire BB starts at 60nm, you can get some very small particles from this process. The net result is that it is easier for the pieces to bond in the roughness of the surface to be lubricated. A 60nm particle is not going to fall into a 2nm surface imperfection. But a destroyed BB part will. So you get a smoother plating of the target substrates with a mix ranging from 60nm and down.
Conclusion: IF works better because it delivers much smaller particles resulting in smoother mating surfaces. And probably sooner than any long term performance of "lesser" particles.
You also raise a point that I have been curious about
il. Inherently oil (shorthand here for anything being used as a lubricant) is designed to get between the substrate surfaces and add a slippery film. When you put in WS2, it will be a lot harder for the surface burnishing to take place because it is being insulated from the pressure and contact it really wants to have. It has to be real bad oil to result in the metal-to-metal interface you would like to have for plating. If the BBs slice with less force than normal particles, it could then improve time to improved performance in an oil carrier.
In an operating engine or gears etc. there has to be an oil to carry the WS2. The best and fastest results would be achieved by the part manufacturer initially plating the surfaces. The material can be sprayed and will bond at relatively low pressures.
Now - guns. For anything that can be used without oil for a bit; the WS2 should be delivered as a powder suspended in an evaporating carrier. Then operated a few times to embed the WS2. That was my thinking for my gun. Alcohol with WS2. I have not fired the gun since I treated it. But I did work the slide and action many times. I have multiple identical guns and the second one will get some Millers Oils nano oil. It will not be a completely fair result because I am going to replace the trigger group on the second one before lubing it. I will exercise the slide and trigger like I did with the first one (dry fire is OK). And when we can buy ammo again, I will do some shooting. These guns are known to be built to very tight tolerances (they are a work of art) and will change significantly after a few hundred rounds. This means it is not really a good testbed because there are more than one changed factor involved in results. But what I mostly care about is getting them operating as well as I can. I could take a third one and break it in before applying anything; but I won't. There are a few parts inside that the manufacturer recommends be lubricated with a MoS2 grease because of extreme pressures on the surfaces. They are so lubricated from the factory. He uses a grease with Graphite in it - which I don't like. This may mask some of the WS2 effects on those parts. I clean all of that off before I use them. And they probably have not fired more than 7 rounds during factory test. Plus maybe 14 rounds of mine (standard pressure) through the one I have lubed. I could ask them how many they fire. Further violating the basic rules of experimentation, the second gun is black and has a "self lubricating" finish. It will be awhile before I figure out if I am improving anything. If nothing else, I do not think I am doing any harm.