My wife’s ancestor, Juan de Santiago (the family name was changed to Santiago de Escobar, and ultimately to Escobar) in his death record in the Asunción de Maria church records in Aguascalientes, Mexico, was said to be almost 100 years old (his baptismal record exists, and though was quite old for the time, not quite 100), and to have had 45 children from three wives.
I have found documentation for all of the wives, including a dispensation as two were related, and what I relieve to be his signature.
I can account for 25 of the children. I suspect there were a number of stillbirths, these would not be in the baptismal or burial records, as stillborn children cannot be baptized and would not be buried in hallowed ground (the church cemetery).
The family as a whole is reasonably well documented in the Mexican church and civil records and branches are in Mexico, various states in the US, Spain, and Canada.