Actually there's more types than that. Sounds like you're describing the British Type, not the European type. What I picture for European type is like what they have in Germany, slightly heavier set. But slightly less of a tail than American type. I expect it's the same in the Netherlands but I'm not sure.The only thing I can think of is that the line of birds they are referring to are Dutch in origin, and have more of a European type, and not the type/conformation that the U.S. standard calls for. European Leghorns have pinched tails and huge oversized combs, so are very different in type/conformation than U.S. Leghorns.
Otherwise, I see a lot of birds advertised as or that and the sellers have no clue about the breed they are selling, or the bird isn't at all what the breeder says they are. So in those cases, it is anyone's guess what you are buying.
Yes, I find show type Leghorns to be a lot mellower than the flighty Leghorns folks always complain about. Same with the Anconas I had. They had lovely, active personalities but they weren't flighty at all.The two lines of Brown Leghorns I have are as different as daylight and dark. The line from Don Schrider have slower developing combs and calmer dispositions, while the other line have huge combs and are very flightly. So far, the flighty line seems more close to the European standard, with their large combs and their tails seem to be held tighter together and less spread than the birds from Don Schrider's line.
We will be using the birds from the flighty line as strictly layers, and only breeding from the birds from Don since I like that they are calmer and more docile. And their type and color are far superior to the birds from the other line.