You'll get some leads where the husband's coverage is free but they're paying $500 a month for the wife and child. In those cases you had 'em at hello. Yank the wife/child off the group plan and save them over $200 a month. Nothing to think about.
Another reason you might not want to take a wife off a group is if they are planning on having more children. Thats the first thing I ask before recommending going from a group to individual!