Now....when I was a CSA....back in the dark distant days of the late 80's....It was common unwritten policy to never let the pax see the seating plan, especially on a charter (it was all manual check-in in those prehistoric times).
If any pax offered any kind of bad attitude..then if they wanted non-smoking, they were shoved in smoking and vice versa...
However, a polite attitude usually resulted in the pax getting whatever they wanted..
Timmcat, at least they sat you all together !