The only reason Canada gets 'invited' to these wars is to show that the world supports the US or Brit decision to invade. Remember, that Canada's refusal to join the trip to downtown Baghdad was very upsetting to the US.
If you look at what countries contribute and the restrictions on employment in theatre they set, some contributions are not much more than window-dressing. During IFOR/SFOR/KFOR, some contributions were not allowed to participate during hours of darkness. In Afghanistan, some contributions were only deployed to areas where there was very little action.
Its true that Canada had only one battle group active in Afghanistan plus the National Support Element (NSE), but we had another BG equivalent involved in the hearts and minds operation through the OMLTs, CIMIC, and other rebuilding efforts. Our total contribution was some 3200 troops, not just 800.