I imagine Chicago has the puck so much they don't have time to throw hits.
This. Lack of hits is more of an indication of puck possession then how physical a team is. It is interesting that some of the teams that are known for their physicality are all over the map in regards to amount of hits they have this season. LA (2nd), Philadelphia (6th), Boston (11th), St Louis (13th), and San Jose (27th). Hell, one of the most physical teams this year is Calgary as Hartley likes his team to play with an edge and tends to employ "goon" tactics. They are ranked 22nd in total hits.
Also there isn't much of a relationship between the amount of hits (or lack thereof) and the standings. Top five teams in hits are Toronto, LA, Columbus, Ottawa and Winnipeg. At this point 2 of those are currently ranked top 8 in their respective conferences. The bottom five teams in hits are Chicago, Minnesota, New Jersey, San Jose and Nashville. At this point 3 of those teams are currently in a playoff spot.
Therefore hit stats can be misleading. A qualitative assessment would arguably be better than a quantitive approach to making an accurate assessment of a teams physicality.