How I would have done Dark Fate differently:
John Connor is still alive. He and Sarah enjoy years of rest and relaxation, choosing to remain mostly off-grid, but with less caution now that the future is seemingly no longer at stake. Until one day, just a few years shy of the present, they overhear a news report of something suspiciously similar to a Terminator; a freak lightning storm, an indestructible man, collateral damage, the usual signs. They make it their mission to track down the Terminator and destroy it and in the process are surprised to learn that John is no longer the target. The following years bring more reports of Terminators, and the Connors form a team of Terminator hunters. This plays into the theme of the first movie’s impending “storm”. Sarah’s friends with the weapons stash from T2 could join. Maybe John reconnects with and recruits his red-headed pal Tim. Maybe Kate Brewster or the Dysons join them somehow
Arnold is not in this movie, and the Terminators are all vastly different in appearance with actual personalities. There’s no replacing Arnold — or even Robert Patrick for that matter. Technology has improved enough that cybernetic organisms from the future would likely be able to infiltrate and adapt much better. They wouldn’t be stoic killing machines unable to blend in with those around them. Dark Fate played with this idea by having the Rev-9 put on a personality a couple of times, but he wasn’t much different than his predecessors, and his design wasn’t too far off from anything we’ve already seen. Arnold is irreplaceable by a single actor, but the T-800 model can’t exist without Skynet. Since there’s clearly only so far you can alter the design of a Terminator, why not just include a small group of five or so individuals with varying abilities? One could have detachable drones on its body under its skin. Another could fly with rocket boosters. Another could use liquid metal tendrils. There could be a Terminator disguised as a dog. Maybe one is a crazy guy who glitches a lot. The possibilities are endless for capabilities and personalities.
The new Judgement Day is still a couple of decades off, and Dani is a young girl, close to John’s age in T2. In my alteration, Grace arrives from the future at the same time as an entire group of Terminators. After listening to police reports, Sarah and John who are closest to Grace’s location mistake her for a Terminator and pursue her. After a short scuffle they realize they’re on the same side, and Grace is able to offer some clarity on the new future and the Terminators’ new Target, Dani. Because my version builds on previously established characters; I think one of the major themes should be John coming to terms with no longer being the future savior of mankind, and not only that, but the fact that he himself put a stop to his own destiny. In a way, new Terminators showing up gives him some purpose back, but he is somewhat conflicted in settling into a lesser part in the grand scheme. Here he’s taking on the role of protector, mirroring that of the T-800 from T2, trying to keep a young Dani safe.
So after formulating a plan with Grace, John and some of the other Storm Chasers head directly to Dani to protect her while Sarah, the rest of her group, and Grace who has a built in system to track the Terminators attempt to stop the villains as they close in around Dani’s current location. Grace’s need for meds was ultimately little more than an inconvenience, so I’d also write that out. Sarah bonds with her, as she sees some of herself in Grace. Grace’s motivation remains the same. Sarah considers the idea that humans will seemingly repeat the same cycle of creating a system that will destroy all of humanity unless humans stop it. Are we doomed to become our own destructors and saviors forever? Can we ever change?