Fisher has coached full seasons from 1995-2010 with Houston/Tennessee, and from 2012-current with St Louis.
He made the playoffs in 1999, 2000, 2002, 2003, 2007, and 2008. That's 6 times in 20 seasons, and that will probably be 21 because the Rams have an outside shot at the post-season.
Lewis has coached from 2003-current. He made the playoffs in 2005, 2009, 2011,2012, 2013, 2014 and 2015. That's 7 times in 14 years, 15 since the Bengals have a low shot at the post-season this year. The issue with Lewis is he hasn't won a playoff game, though the last two losses he was injured riddled (2014, AJ Green, Mohamed Sanu, Tyler Eifert and Marvin Jones were all out IIRC, and Rex Burkhead had to play receiver
). Then last year his starting QB was out. Fisher hasn't even made the playoffs in STL and there were talks of an extension...