My understanding from several friends whose parents are buried in different military cemeteries is that spouses are buried on top of one another which is why names appear back and front on the stones or one above the other on the same stone. So it doesn’t take more space for the spouse to be buried before the vet dies or after. And presumably children could be included in the stack or they could be cremated and aligned or scattered. Ashes for spouses can also be combined. There are options. The souls are departed. But I see no reason why a practical solution can’t be worked out for families to be buried together without it becoming a space issue. People may just have to cooperate. I get that’s a nasty word for republicans so my expectations are low. But especially spouses should be allowed to be buried together no matter who dies first.