For the next game, we should have characters that aren't really characters, but classes.

Like those flying demons in MKX's story mode, or those cattle prod-carrying Red Dragon goons from those sketches a while back when MKX was in development, or Shadow Priests, or those guards on Shang Tsung's island. I think Meat could be made into a class of Netherealm demons.

Their purposes would be to give playable characters in story modes commonly fought foes, and to spare most named jobbers like Baraka and Erron Black from being jobbed out more than once, to make them seem more special as opponents. That's one thing the MK movies, even Annihilation, did right, by not jobbing out the enforcers more than once in the same movie.

To conclude, being playable, they would have full movesets, intros, outros and even endings, but no definite personalities. Their intros could either be like the MKX guests', with them not speaking, or whoever their leader is would be there to do the talking, getting the lackey to do the fighting and disappearing once the fight starts.