Don't underestimate the czech czech glass is vastly superior to everything ever made in England. The biggest british achievement in glass was Pilkington and their floatglass other than that their glass was more middle of the run. The truth is that if it was invented or made in the east it's seen as inferior by the west while in reality a lot of products from eastern or in the case of the czech republic center of europe are equal or superior to western products. That includes glass.
I agree with you that Nash was the genius behind Tiffany and before Nash it was John LaFarge. But both is needed the artistic input from Tiffany and the knowledge from Nash/LaFarge without the artistic ideas the latter two wouldn't even have had the idea to create something in the line of favrile glass.