With due respect, Chain Singh has been in much better form in the past 2 years while Gagan is a legend who is in good form as well. So, sadly if Sanjeev Rajput was selected it would have meant 1) Either Gagan Narang or Chain Singh, who are in decent form would have missed out on atleast one event 50x3 or 50 prone (or Rio if Sanjeev was selected to start in both) and 2) Young and talented Kynan Chenai would not have been able to get the exchange quota. So, leaving Sanjeev out of Rio bound team was a tough decision but it was also the correct decision.
We need to stop analysing decisions based on events that happened after the decision was made. Nobody knew Rajput would win silver here, nobody knew Pooja Ghatkar would perform so well. Based on the information NRAI (and we) had at the time of selection, I think NRAI did a perfect job of team selection.