Swampscott Fire Chief Graham Archer has long thought the town should be able to hire the best fit for the job — not just one of two people with the highest test scores — when it comes to the fire and police departments the same way every other town office does. Convincing unions and town leaders who have seen it done another way for their entire careers — as part of a civil service system that dates back more than a century — to push for a change was another matter. But Archer grew convinced in recent years that if he were able to sit down with those glued to the status quo, and got a chance to talk with them about how a change could result in more diverse departments that are more responsive to residents' needs, he was pretty sure he could convince them to leave the state's civil service system that requires hiring and promotions to be almost strictly test-based.