Monument from two surviving brothers

“This monument was
erected by the two
surviving brothers
of the two who sleep beneath:
March 1853.”

T. (Timothy) C. and A. M. Day erected a much-decorated monument in honor of their older and younger brothers, Albert G. Day and E. (Elias) Harvey Day, respectively. Members of the extended Day family are buried in the same section of Spring Grove, seventeen total interments, but only these first two of Elias and Sara Day’s children to die have a grand edifice in their honor. This monument seems to be a sign of brothers’ love. Both Albert G., a printer by trade, and E. Harvey, a confectioner, were born, lived, worked and died in Cincinnati. Both men were bachelors and apparently had no children. The two middle brothers, T.C. and A.M., married and had their own families. Their parents, Elias and Sara, were still living when Albert G. and E. Harvey died. Was that a part of the reason for the monument? To honor the parents?
I am still researching and sorting the family tree. There are 17 extended family members buried in Section 45 of Spring Grove Cemetery. More later....
This is the Day family tree derived from Spring Grove records - there are 5 generations represented 17 burials that are recorded. Where is everyone else?