The works Dakar bikes had low guards , so will have to assume all the works riders wire faries.
Either that or they were riding desert racers in the desert.
And as has been pointed out elsewhere, if you actually ride the bikes , as oposed to taking pictures of them splasing through puddles, you will find that without some sort of a low guard the front you will soon drown the electrics, and most of yourself below the waist.
I have used the flatracer tubular fork brace and a low guard on my G/S for a couple of years withoutany problems, and as the bikes pictured still have the fork brace at the lower level I dont think that fitting a guard to the would cause any problems either.