So the "best" candidates usually come in a few different types in rough order:
1) #1 guys who have been taking care of business, but might want an opportunity to be a #1 in a bigger & better market so they can really compete at the top & take what they're doing & continue to roll with it, but with a bigger budget & better infrastructure. This is the Falvey, Antonetti, Hazen group.
2) #2 guys in successful franchises who have learned from their #1 & from the way their org does business, but are looking to expand on what they're doing & be that captain of their own ship & not have to report to the #1 because they have visions of how they would run things & want to fashion a new franchise in their own image. Otherwise, why give up the very stable #2 job which surely pays very well & has a ton of job security. This is the Gomes, Fuld, Levine group.
3) Successful former #1s who one believes may have gotten the raw end of the deal or have otherwise learned from their previous situation who want a chance to get a fresh start & improve on where things went wrong previously. This is the Click, Ng, Daniels group.
4) People further down a team's management structure who are bright & have learned a lot from their time in their successful organization & have the opportunity to bring what they know to a new spot. This is the Breslow group, & this would also apply to people like Rosenbaum, Sestanovich & Fast if they were looking into others of this ilk.
5) Internal people who will probably mostly keep the status quo but may have a few ideas of how they would do things better, but do not have significant experience doing things any way other than the Red Sox way. This is the Romero, Groopman, Toboni group.
6) Failed former longtime #1s who would love to get out there & get another shot at running a team. This is the Huntington, Hill group (which sounds like a successful finance company). Could add Forst to this pile except for the fact that he's still employed (& not really sure if he's a #1).
The 1st group were never going to be interested because the job inherently does not come with an unlimited runway & they have established themselves where they are & have control & security.
The 2nd group is the one where most #1s come from. & they are the type who will be arrogant enough to think they are smarter & better at this than the people who would be hiring them, & would chaff at all the institutional limitations that appear to be part of the Red Sox job, including several executives who have been through 3 or 4 regime changes, & a manager who will be on his 3rd #1, too, who appears to be loved by ownership. Having smart people in place like Cora/Ferreira/Romero/etc. would be seen as a good thing by this type of candidate...but the appearance that they would not be above these people in the hierarchy & have the autonomy to do what they wanted with them after a short review period, would lead to a lot of questions & concerns over whether it's worth it to get involved.
The fact that the 3rd group seems universally uninterested is a bit concerning as well, but I suppose not toooo surprising. They have experienced hierarchies that they are not necessarily happy with & have enough cache that they can wait around for what they feel is the right opportunity, because they probably aren't getting a 3rd bite at the apple if the 2nd one doesn't work out.
Which leaves the 4th group as by far the most interesting to pull from as there are going to be some really sharp people in that group, & there is a lot of institutional knowledge that would provide support to that type of hire & give that person a chance to blossom, & they are far enough down the totem pole where they are at that the opportunity to jump a few steps while their star is bright should be appearling.
After that, we have group 5 which is boring...& most of the people in it will still be part of the organization & able to provide the same insights as if they all got moved up a rung or two, but I think is probably still better than group 6 as they do not have the same scary track record as the people in that group.
Now some people in lower tiers may certainly be more desirable than people in higher tiers - for example I'm more interested in Breslow (tier 4) than I am in Levine (tier 2), but I think the general structure & order makes sense, & it also makes sense why the top few tiers may not be interested or skeptical. But great candidates can come from any tier & you just have to spot the right 1.