The names or lines used to be important at one time, and still are to a limited extend. However, there are new "lines" being imported every year and the pastels out there are being bred to other lines so the distinction is quickly fading.

I believe it started when some of the big breeders imported pastels from Africa for huge sums of money. Of course they wanted to add their name to the line to show off their investment and get more customers. I'm sure a lot of the lines will continue to be bred as pure, but over time the line will become diluted.

It shouldn't really matter, though. Their are good and ugly pastels of every line and of the lines that haven't been named. Your best bet would be to pick out one that looks good to you and ignore the name.