Not sure I'd call Marty legacy talent, other than he'd been in the market several years ago during a consecutive run. It's been something like twelve years since he was on the air in Seattle. Given the population churn in the market and the mirage that was AAA in Seattle, trying to sell Marty to agencies or local advertisers likely would be a challenge.
And maybe that's where this all leads, a pure 25-54 agency demo play. I just don't see trying to bring KMTT back from the dead as being enough by itself.