My thought process of coming to that conclusion isn't based purely on his statistical production, which you are basing your conclusion on.
The original question was who would you rather keep, Stepan or Brassard. I personally chose Brassard because of the raw tools he possesses that aren't measured by a piece of data. How well he skates, his hands (stick handling, dangling, etc) his ability to shoot the puck (all types of shots, wrist, slap, snap) etc. Not to mention his fire, and compete level which is lacking in Stepan's game. He's a notoriously soft player.
Those raw tools are some of the things he was originally judged on when scouted and eventually drafted in the first round, sixth overall, to Stepan being drafted in the second round, 51st overall.
Stepan has better statistical numbers, so if you're judging him to be the better player that way, I understand and respect it.
When in reference to who i would rather keep, I personally want the more talented guy in the fundamental aspects of the game. Making a judgement on a player based on pure production stats that can be heavily influenced by line mates, and other factors shouldn't be the only thing taken into consideration when determining who should be kept.
Using that same logic, you wouldn't want Rick Nash to play in the playoffs at all.