For the Teutons (or rather the Teutonic Order), when you found a city as them, the city is called Achen.

First: The correct name is Aachen with 2 times A. See https://en.wikipedia.org/wiki/Aachen#Middle_Ages

Second: I would put this city as the first one for the Franks if anything, not for the Teutonic Order. I don't know which city the Franks get as their first in the game, but at that time, Aachen would be Frankish. The Teutonic Order "settled" much further in the east of Europe, so I'd either pick something from there or pick the founding place of Acre (Akkon) as their first city. Two good alternatives would be Malbork (Marienburg) and Königsberg, if they are not already in the game.

Third: Since we're already on the topic: I also want to point out that Teutons (as you call them) and the Teutonic Order (what you actually mean in game) are two different things that are separated by ca. 1000 years. Teutons is a people group/tribe that fits in the Ancient era, Teutonic Order fits in the Medieval era and that's what's portrayed in the game. So my suggestion is to rename them accordingly, but the First and Second points should be a higher priority.