Which tomb, this one or the one at Pydna? You are already making it a fact that it's Olympias' tomb. It could be, but you are presenting it as a hard fact without any evidence.This might support a working hypothesis that Cassander wrecked and closed up Olympias's tomb
By the way, the head of the sphinx may be around 180 kg, not that easy to move around. It was found in the third chamber, if the other is there too, is it possible this was part of a ritual during the burial of the dead? Also, if Kassandros had destroyed the tomb then why would anyone seal it with not one but 2 and possibly more walls?