I thought length of service was giving furloughed guys credit for time they had spent on property, not time being on furlough status.
The example would be a guy with 6 years on property but is currently furloughed being given credit for the 6 years he had been active versus a 3 year active pilot at the other merger partner.
In some SLIs the furloughed pilots are placed below active pilots, in others the time on active service is taken into consideration. It all depends on the circumstances and the way the arbitrator looks at the facts.