Scaling a Google Map is always an approximation. For permit sets, grading plans, or legal descriptions, you must trace the map with CAD geometry (polylines, arcs, lines) and then scale the vector geometry , not the raster image. The raster remains as a visual reference only.
The image should now be scaled correctly. how to scale google map in autocad
Google Earth Pro (free for desktop) solves the two biggest problems of screenshots: it maintains geographic coordinates and allows export of georeferenced images. Scaling a Google Map is always an approximation