I can, and I did, but leaving the top one out would feel really odd because he's obviously a closer match. Basically, there are about three closely overlapping topics I'm interested in, and three corresponding professors. I'm mostly interested in Professor X, topic X, so I emphasized it the most in the SOP. I also talked about Y and Z, but not as much because they're my second and third choices. So should I re-do my SOP and leave out the X stuff? Or keep that stuff, and still mention Professor X?