From what I understand (and this is from an exceptionally reliable source), Culverhouse and Karsa ran the show Monday to Thursday with Lambert often not even in East Anglia until Friday. It was the perfect combination of the tactical nous of Culverhouse and the motivational leadership of Lambert that brought the success. Karsa just helped to pull it all together, he was Lambert's eyes at Colney during the week.
At the time Ian had no interest to manage, he was very happy as Lambert's number two and as outlined above by Kingsway he saw a future as the next Mike Phelan (to Lambert as Ferguson), in the background but known to everyone as the brains behind the success.
It was only after the falling out that Culverhouse decided he needed to try to make a go of it as a manager and this took him outside his comfort zone. He didn't want to be talking to the media, or being the one to motivate a team, but Kings Lynn was the perfect way to start this.
My source tells me that he'd love to manage Norwich one day and that the feeling is mutual from the club. He's very well respected in the boardroom at Carrow Road.