I wouldn't put the Chargers in as an elite just yet. Their recent stretch of wins includes 2 wins over KC, a win over Oakland, wins over struggling and slumping Denver and Giants teams, and a win over Philly. Not exactly an impressive resume of wins over teams that are good or playing well.
I think there are three great teams in this league right now. Minnesota, Indianapolis, and New Orleans. After that there a large group of very good teams like NE, SD, Cincy, Dallas, Philly, and Arizona and maybe Pittsbugh, the Giants and Denver.