The big danger with fenders, especially in an offroad situation, is that a stick or something will get wedged between the front tire and the fender. When this happens, the fender can get folded in and lock the front wheel resulting in you doing a severe face plant before you know what's happening. My understanding is that having the fenders closer to the tire makes this more likely. SKS fenders have a break-away clip that is supposed to prevent this.