I found strange to get シアトル市 on level 3.
Although I understand that one of the reasons can be to teach how 市 is added to a city, I found strange that this city came so early, as it’s not one of the most known cities around the world. (I knew it from the former NBA team and Grunge music, but those things are getting a bit old now)
Is there any reason I can’t grasp?
Maybe the katakana characters? Someone on the team from Seattle?
It’s not a criticism, just pure curiosity.
Pretty sure Koichi (website founder) is from Seattle
Agreed. I have seen somewhere the mention of Oregon next to the name of Koichi, so pretty sure he is somewhere from the West Coast. Plus, as far as I know, Seattle is one of the West coast’s tech hub, so it would make sense to pick an example which is the most relevant to you.
Less so these days, but there’s still a lot of people in Japan who will perk up at the mention of Seattle because Ichiro played for the Mariners.
(That has nothing to do with why its in the vocab list, but it IS fun for me when I try to talk about where I’m from)
Japanese people don’t usually leave the mothership to move to the US unless it’s to Honolulu, California, or Seattle. Honolulu makes sense. No idea why they picked Seattle. 
Wikipedia suggests it’s because Seattle essentially violently forced out all the local immigrant Chinese (culminating in a riot in 1886), which left more of an economic opening for subsequent Japanese immigrants compared to other west coast cities.