The FO might be about low risk, but do they really tend to go with the guys they know? Payton was obviously an outsider, as was most of his staff. He then proceeded to bring in multiple DCs with no connection to the Saints until he got to DA. Yes, they hired DA off of his staff, but they tried to hire Coen, an outsider, as his OC but he turned them down so they kept Pete. Then when they realized they needed a new OC they went way outside of the usual and brought in Kubiak and his entire staff that have no ties to the Saints. Loomis even brought in Ziegler and Ireland who before they got here had no connection to the Saints. So, in the end, it's really only DA and recently Mueller that were really familiar to the Saints that were brought in.
And, the truth is that all teams tend to hire guys they know or who they are connected to. It's a league that is all about getting jobs through connections just like most of the rest of the world.
And most teams are looking to hire the HC that has the least risk. Nobody hires a HC because they think he is a huge risk. They might decide to take a risk, but if they do it's only because they have a conviction that he's the best coach.