I've shot light weight poundage bows bowhunting for deer for the last 48 years. Most of my shots are between 12-17 yards. They've all been broadside lung shots which takes out both lungs. No animal goes far without lungs.
So, to sum up. For a light poundage bow on deer....short yardages, broadside lung shots equals meat in the freezer.
If you look at my signature, the lightest bow I use for deer is 37#.
Conventional wisdom for light bow poundages says to use a 2 blade broadhead. Since I use light bow poundage, I went against conventional wisdom and shoot a 3 blade Muzzy 75 grain broadhead, but it's only 1" wide.
This combo gives me a good blood trail with short recovery distances due to the double lung shots I take along with short shot yardages I take.