For what it's worth when I went to use a set of fenders I had off a 26" wheel on my 700c bike I found the stays were too short. I made some "fender stay extenders" from aluminum for both the front and back. Lots of miles and no issues.
What I found was they worked nicely as a means to adjust the fender spacing and side to side spacing also. You can see the rear ones in this photo where the stay attaches to the bike.
For a road bike those fenders are too far from the tires. If you ride in Germany they will probably give you a ticket