Regarding fitting V brakes on a large fender over a large tire, this might help.
https://www.gravelbike.com/v-brake-arm-lengths/
Using that information, I bought the Tektro 857AL brake for my bike (not an Atlantas) because of the long 110mm arm length. My fender is 65mm wide and I often have 57mm wide tires on the bike.
I hope the photo is not confusing, i am running a Travel Agent on my brakes so I can use short pull brake levers.