All they have to do to speed up the process while not rushing it is to just pull a Shaolin Monks and go straight for MK2's Storyline. This could be the way the movie goes:
-Lui Kang vs Shang Tsung (with fights like Scorpion vs Subzero being short flashbacks)
-MK2 Story all the way until they rescue Sonya and learn of the upcoming Invasion (Skipping Unnecessary fights/events)
-MK3 Events where Earthrealm is being invaded while the heroes need to return to Earthrealm (No fights needed)
-Nightwolf, Kabal, and Stryker arrive for an MCU Spider-Man style appearance (Fighting Kintaro, Ermac, and Reptile. No Noob in this movie)
-Sindel's Massecure (Keep Kuai Liang Alive since his death meant nothing to his development)
-Kahn Successfully invades (without Raiden's help), kills Lui Kang, gravely injures Kung Lao, and gets defeated by Raiden
-No mentions, cameos, or anything involving members of the Brotherhood of Shadow. Only Scorpion should be in this movie. No mid-credits scene either just incase the movie flops. That way those who like it won't get mad about a cancelled sequel and those who don't will have hope that their won't be a sequel.
After that, they have free reign to tell the stories they want. I know the idea is getting overdone, but I'd suggest a mini-cineverse to fill the holes of the Blood God Story (remixed), The OIA Story, White Lotus Society (with Kung Lao training Kai), and Outworld Civil War leading up to a movie for MK4 & and second half of MKX with Kung Lao, Raiden, or Kai being the one to defeat Shinnok. All I know is that the very last movie HAS to be Armageddon, but done right and only done with the already established characters.