Arlington Cemetery, on the recent map I have directly in front of me, is located near Drexel Hill, a short distance to the west of downtown Philadelphia and an even shorter distance from the old Cedar Ward where my ancestors resided. Unless my map is incorrect, it appears your information is incorrect. Perhaps your confusing the national Arlington Cemetery?
One has to wonder what became of the grave stones if they weren't moved, and whether anyone recorded the information thereon for posterity. I haven't given up my search for that information but the public servants we've dealt with thus far have been less than helpful and in the case of my brother-in-laws inquiry, full of "attitude." Thus the "neener neener," my attempt to add humor to our frustration. It comes from a chidrens game. Or to put it another way - it means nothing.