I don't have any reason to dislike this guy exactly but I also don't see any reason to be excited either.
Leonhard we all know about but even Parker I think has a very similar profile in terms of NFL coaching experience. I prefer Leonhard because he was a high level DC in college for several years but Parker is similar outside of the college experience.
Both have been "passing game coordinators"/DB coaches for elite defenses under elite DC's (with elite secondaries) over the last two years. Leonhard has the added "assistant HC" title, but Parker is a guy who Fangio seemingly loves and has quickly given him added responsibility in a very short period of time at two separate stops. Bottom line is both are fast risers and have played prominent roles on elite defenses, with elite position groups, at young ages.
With Leonhard I like that he had a hand in developing a bunch of so-so talents at Wisconsin who have gone on to become excellent NFL players, largely due to effort, intelligence and physicality, not elite physical talent. With Parker I like that he's been the coach of a unit that has hit big on 3 high picks at his position group in just two drafts with Mitchell, DeJean and Mukuba. They were all 1's or 2's to be fair, and obviously those picks aren't all because of a DB coach, but hitting on 3 straight picks on a specific position group in two years no matter how high the picks are is impressive.
Jones on the other hand is kind of a journeyman, bounced back and forth between college and the NFL, and was never really part of a good defense until he linked up with Flores in Minnesota. In fact, the defenses he was on prior to Flores with the Vikings (Dolphins 2016-17, Bengals 2018-19, Vikings 2020 and 2022) were pretty much universally terrible.
Maybe he's some sort of savant who has flown under the radar but those interviews better have been mind blowing if he ends up being the guy.