"as they were merely variations on earlier Colts."
Actually, they weren't, other than the fact that the guns had similar parts and served a similar purpose, their mechanics were quite different.
But, one could also claim that the 1911 shouldn't be on that list, then, becuase it's similar to other designs that were also being developed in Europe independent of Browning.
Or that the High Power should be on the list, since it's simply a variation on the 1911.
The importance for both lies not in their innovation qualities, but in their overall acceptance and their subsequent influence.
It's likely that more Hand Ejector/Hand Ejector direct copies have been made than any other type handgun. They were, for over 50 years, THE standard for police use in the United States.
Well over 1 million of them were made during WW II and supplied to combatant nations, in many cases being used in combat.
The Hand Ejector also, as the article indicates, served at the initial platform for several of the most popular cartridges of all time -- the .38 Special, the .357 Magnum, and the .44 Magnum.
Colt's revolvers, for whatever reason, never approached that kind of acceptance.
But, if you're going to use the criteria that one particular gun doesn't belong on the list because it's a variant of another, earlier gun, you'd end up with a list of fewer than five.
1. 1911 - already talked about that. Out.
2, 10. Hand Ejector, talked about. Out.
3. Glock 17, neither striker fired or polymer construction were innovative. Out.
4. S&W Number 1. This one comes a lot closer to being new and innovative. First use of the bored through cylinder, first use of a break action to access the cylinder. But, the cylinder indexing was dreamed up by Colt. Out.
5. Volcanic. This one may be the first true original on the list. Tentatively in.
6. Colt's SAA. Used the bored through cylinder, which was invented by a Colt employee, refused by Colt, sold to Smith & Wesson, and introduced in their Number 1. Out.
7. Walthers... These may be innovative enough to be on the list. But, blowback operation was pioneered by many others before the Walther came along. Out.
8. Mauser C96. As far as I know, this was an innovative design in all aspects. Tentatively in.
9. Browning High Power. Same as the Colt 1911. Out.
So, there you have it. The list of the two tentatively greatest handguns of all time.
Greatness isn't just about technical innovation. It's also about acceptance, longevity, and utility. When you start thinking like that, and being bound by it, you're not going to get to the heart of understanding why some handguns are still in common use after more than a century.