Hello Kai2z;
 Thank you for reaching out, I changed the classifications for some ways to maintain the classification hierarchy for the area.
for example:
https://www.openstreetmap.org/way/338515329
this street is not suitable to be a highway=tertiary with the surrounding streets with highway=residential.
In my opinion, the main ways in this area need to be with "highway=unclassified"
Also if you have an official sign for the maxspeed it will be helpful to add it and upgrade the classification.
Regards
little_maper