I'm in the belief Swift landed in the worst possible spot for a RB and it has zero to do with Kerryon Johnson and everything to do with being a Detroit Lion. The Lions have been awful at running the ball and having useful FF RB's since Barry Sanders retired. The reason for this falls into 3 categories - poor offensive lines, bad coaches/management, and injuries.
Here's how Lions RB have performed in FF for the 21 seasons since Barry retired. *All numbers determined via FootballGuys historical rankings*. In PPR, the Lions have had a league worst two RB1 finishes (Reggie Bush as RB7 in 2013 and Kevin Jones as RB12 in 2006). They're fifth worst for total number of RB1 and RB2 finishes in that time with many of those RB2 finishes just barely cracking the top 24. If broken down into number of top 20 FF RB finishes they'd be last in the league. Only 1 Lions RB (Joique Bell) had multiple seasons of finishing as a top 20 FF RB while in a Lions uniform in 21 years. It gets worse in standard scoring for Lions FF RB's. Last in RB1 finishes (only Bush as RB10 in 2013), last in RB1 and RB2 finishes, last in top 20 FF RB finishes, and zero Lions RB having multiple top 20 FF finishes in a Lions uniform. For PPR and standard, the top scoring Lions FF RB has had the worst average FF RB finish among all teams during the past 21 years. The Lions haven't had a PPR or standard FF RB1 or RB2 season in the past 5 years, the entire Quinn era.
It'd be easy to write off everything above saying the Lions have had terrible RB's during the past 2 decades and Swift is the best RB prospect they've had since Barry retired. The Lions have certainly spent a bunch of draft capital and brought in decent free agent RB's during that time frame. They've spent late 1st round picks on K Jones and Best, early-mid 2nd's on Leshoure, Abdullah, Kerryon, Swift, and the first pick of the 3rd round on K Smith. Free agents they've brought in are J Stewart and Bush. Among the draft picks I'd rank Swift second behind Jones, a 3 down RB with receiving ability (he had 61 receptions the year he finished RB12 in PPR).
How could a team that's invested this much into the RB position be so terrible at producing quality FF RB's? Let's start with the offensive line. *All numbers pulled from Football Outsiders*. The Lions have had the worst run blocking in the league over the past 21 years and it's not even close. During those 21 years they've finished in the top half of the league in run blocking just 3 times and never finishing higher than 13th. On the opposite end, they've ranked in the bottom 3 a whopping 11 times in 21 years. In the Bob Quinn years they've finished no higher than 20th and bottom 3 twice in his 4 years. The offensive line for 2020 doesn't look promising either after watching their best OG leave in free agency because they didn't want to pay him. For 2020 they'll have an average/sightly above average LT, a very good C, a free agent signing at RT who played great in spot duty but hasn't been a full time OT yet, a rookie at one G spot with the other being a below average player. An injury to either the LT or C would leave this line in really rough shape.
Now with the coaching/management. Not much needs to be said about the Millen and Mayhew (Millen Jr) years. Quinn hasn't done much better. Did you know no former Lions head coach has ever been rehired as a NFL head coach once he was fired from the Lions? How about the Lions having a league worst 1 playoff win (every other team has at least 3) in 60+ years? How about no division titles in the past 25+ years (only Cleveland has a longer streak). The bottom line is the Lions have inept coaching and management that is constantly hiring and firing coaches. Management does a poor job of drafting and retaining lineman and the coaches aren't good at coaching them up. As alluded to in the Lions letting their best guard, in his prime, leave in free agency this year - management has let quality lineman leave in free agency, during their prime, over the years ranging from Compton (Super Bowl champ on Brady's first Superbowl team), Hartings to Pitt, Warford to NO and now Glasgow to Denver. The problem for Swift is you're counting on Lions coaches/management to provide him an oline and utilize him well to become a reliable FF RB even if you're not a Kerryon believer (I'm not). Opportunity isn't the issue here, it'll be there whether it's this year or in year 2-3 depending when Kerryon is gone, it's the expectation Swift's talent will be utilized properly by bad coaches. And maybe Patricia/Quinn will be gone after this season. But even this brings problems. The first is counting on the Lions to hire a good coaching staff which is unlikely. The second is Swift now becomes a guy who wasn't drafted by the current regime. And third, the new coaching staff would have to run a system that is favorable to Swift. There is no continuity with the Lions - they cycle through coaches every 3-4 years.
Last is the injuries. We shouldn't predict injuries but I think it's fair to look at past Lions RB's both on the field and in the pre-draft process to see if Swift has a higher than normal injury risk. Out of the 7 high draft capital RB's mentioned above we know in the pre-draft process that Best (concussion), Abdullah (nagging leg injuries), and Kerryon (hasn't played a full season since high school) were injury risks. All 3 of these guys went on to major injuries during their time as Lions with Best being forced to retire from further concussions, Abdullah suffered a lis franc injury but has managed to do ok as a reserve RB in Minnesota, and Kerryon has missed the better part of his 2 seasons thus far. As for the other 3 guys with cleaner health during the pre-draft process - K Jones suffered a lis franc injury on the field and was never the same, Leshoure blew his achilles before the start of his first NFL season and was never the same, and K Smith was relatively injury free, just the least talented of the the bunch. Now let's look at Swift. Two of the knocks against him going into the draft were he's never carried a full load and has nagging ankle/foot injuries. I think it's fair to say he's a higher injury risk candidate than normal. Maybe it's the curse of the Lions RB position.
Talent triumphs over situation when it comes to FF RB's. There's exceptions to every rule though and there's enough evidence when it comes to the inept Lions and their running game that the Detroit situation >> RB talent. There's a decent chance Swift's terrible situation of landing in Detroit will hold him back from reaching his potential. I'd love to be wrong and see Swift become the next great Lions RB and be an elite FF RB. Maybe he will be the one to break the Lions mold and thrive. It's tough to believe that will happen given their history. I'd feel much better about Swift's FF potential if he was on any team other than the Lions.