Of course a WG cannot be compared to a Python; the latter benefits from years of development, better powders, better manufacturing methods, far better steel, etc.
But to compare the WG to an SAA, the situation is reversed. The Webley was a much more advanced design, a good double action, a better SA than the Colt and, needless to say, much faster loading. The British cartridges were less powerful than the .45 Colt and .44 WCF, but were generally adequate. And no topbreak will be as durable in the long run as a solid frame or a swing cylinder gun.
Americans instinctively react to any criticism of U.S. products, always believing that their (fill in blank) is superior because it is American. But if that is always so, why do we continue to buy goods marked "Made in China"?
The U.S. guns of that time had one advantage, though, an industrial base that was ahead of the English in turning out quality interchangeable parts with little hand fitting. That didn't really make the guns better, but it did make them more suitable to the military environment.
Jim