It would be great if the anemometers were accurate. I've come to the conclusion that most of them have their own individual quirks that I just make allowance for. A good example is the Swanbourne one that
always reads a few kts low, so I account for that when I'm checking it out (I was bitching about it a year ago).
I guess the problem would be if it was inconsistently inaccurate... then you are screwed