Got a basic bike computer and took it out on its first run today

Something dawned on me though. Even though i put the wheel size in, wouldnt the sensor placement matter more? For example, for someone with disk brakes, you could put the sensor farther to the edge of the wheel. I have rim brakes,and had to mount the sensor quite a bit lower. Wouldnt my sensor come around more frequently than the one with a disk brakes, thereby giving me a falsely elevated speed and distance reading? Thats even eith wheels that are exactly the same size?