I think Nokia's marketing is a little confusing.
There are just too many Lumia devices.
From their site, just clicking - show mobile devices - brings up...
Lumia 1520, 2520, 1020, 925, 928, 620 521, 520, 822, 810, 820
Lumia 930, 630 Can add these two to the list when they are announced at build.
What makes it a little more confusing is higher numbers don't always mean better.
Also the 2520 isn't even a phone, it's a tablet, but was listed along with the other phones.
It just seems like a lot when compared to
iPhone 5s / 5c
Even if you use old versions of IPhone and Galaxy the user gets a clear picture - iPhone 2 / 3/ 4...
Is there a reason you've forgotten to mention all the other (current) Galaxy SKUs?
Not to mention the iPad version numbering system. I'm not sure the iPhone system was that logical, either (iPhone/3g/3gs/4/4s/5/5s/c).