Zoos are becoming facsimiles - or perhaps caricatures - of how animals once were in their natural habitat. If the right policies toward nature were pursued, we would need no zoos at all.
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.
