I think Pete's legacy is a little bit more clearly defined here than the question of quarterback legacy. For starters, he has two more years to work with. And his legacy is very clearly defined; he wasted no time in replacing almost the entire roster to his own guys, and the last couple of years were 100% the legacy of him and John Schneider, sink or swim. There was no question about whose guys were really making a difference.
And so if we compare things, Pete is already well ahead in almost every category but longevity. Holmgren was arguably the best Seahawks coach before Pete, and Pete's got him flat beat when it comes to results that count. More than just the Super Bowl win, playoff wins, double digit win seasons, division titles, playoff appearances and wins, you name it.
My take? With this Super Bowl win, Pete just edged into first place.