I think that there is enough variety in games being played by the club that there is not much need to try and schedule activities or themes so specifically. On any given Thursday, all of the activities you mentioned happen. We use the weekly challenge threads to set up singles and doubles games. Campaigns happen when a member takes the initiative to run one, and there are people painting every week.
Remember that not everybody wants to paint at the club (in fact, not everybody paints), some games are not conducive to singles, or doubles, and not everyone is into campaigns. Trying to implement these specific ideas could leave some people out. The flexible "helter skelter" approach accommodates everyone, and leaves room for members to step up and arrange the games they want to play or organize campaigns or whatever.