Trust your gut instinct over spreadsheets. There are too many variables in the real world that you simply can't put into a spreadsheet. Spreadsheets spit out results from your inexact assumptions and give you a false sense of security. In most cases, your heart and gut are still your best guide.
To paraphrase Jane Austen, it is a truth universally acknowledged that a married man in possession of a vast fortune must be in want of a newer, younger wife.