My adivise is to load one chair in the scene scaled and positioned as you like, save that as a prop, use Poser File Organizer to externalize the geometry, load additional instances of that new chair prop and position those, 'memorize' all from the menu or individually on the properties panels, select the first chair and save to the prop library clicking "select sub-set" on the save dialog and choosing the other chairs... the chairs will be saved as a group with individual 'starting positions' and referencing a single .obj mesh data in the geometries folder.