Say the lawsuit is originally against just Holman Fleet Leasing and FedEx is the one legally liable (Maybe FedEx is the one that is doing something naughty. Maybe there's some contractual language around Fedex assuming all legal liabilities for the vehicles sold.). You're going to spend a bunch of time in court arguing with Holman about if they're even the right party to sue, and your case is either going to get thrown out or you're going to lose. Meanwhile, the statute of limitations is still ticking, so if it takes a long enough time to adjudicate the case against Holman, you won't even be able to refile the same case with the correct respondent. Oops. but if the statute of limitations miraculously hasn't run out yet, that's not even considering the possibility that the kind of person who would roll back an odometer would also have a punishingly short document retention policy, so all the documents that still existed at the time you filed against Holman have long since been shredded and destroyed, so your discovery in the new case against Fedex is going to be a single email saying "yeah, we don't have anything going back that far. Oops again.
Now consider the lawsuit filed initially against both Holman and Fedex. Assuming your list of respondents is complete, the case isn't going to get thrown out because you sued the wrong person. Liability will still be adjudicated (and the case amended to drop respondents as the proper liability holder gets determined), but now you don't need to worry about the statute of limitations running out as you wait for the determination of liability against the first respondent. And the document retention clock starts with that lawsuit and covers the time where you're just determining who hold liability, so now they can't delete those documents even if they other wise would be. Both of them are now going to be legally required to retain all the stuff you list in discovery for the duration of at least their involvement in the case. Sure, they could destroy those records anyway, but that sort of thing is regularly used to infer guilt of the respondent with the worst possible inferences when it's destroyed in violation of discovery.
I've learned over time, it doesn't matter how righteous your defense is - all that matters is the money it'll cost to make the issue go away. Turns out, it's almost always cheaper to write a check than defend yourself.