I think Asperger's as a term should be retained.
Hans Asperger described it in 1944 and as far as I am aware no one has seriously contradicted or refuted his studies.
Hans Asperger is still frequently quoted.
If you want a widely recognised definition of Asperger's then all you need do is refer to his work.
The problem with the sliding scale approach to conditions like this is that it can extend at one end from 'normal' to the other end severe, I believe that putting normal to severe on the scale measurement risks over-psychiatry on one end and a belittling of severe conditions at the other end.