Show me you haven't spent a lot of time in Maryland without saying you haven't spent a lot of time in Maryland.
I'm not sure what the point of such an exercise would be, but if you are going to start creating arbitrary boundaries around 26 sq mile areas of DC suburbs to get lower numbers my advice would be to do so in the Virginia suburbs. After all 3 of the safest counties on the list, including the one I reside in, are in the top 10. I'm sure you can craft a gerrymandered congressional district looking area from the 3 counties that beats Arlington.