I don't have a problem with Sting being used in this role, as long as Bully Ray walks out champion, and does so having won clean.
I'd venture as far as to say that they had to do this match. Simply, it's the only logical choice. While the entire locker room, theoretically, has a beef with Ray and Aces and Eights, it's personal for Sting. He vouched for Ray, only to have Ray do the very thing Hogan was wary of, with Sting eventually convincing him otherwise. People are disappointed that Morgan lost to Sting, or that a younger star wasn't given the shot, but where else could they go? You get a rejuvenated Sting in a revenge angle against the guy who stabbed him in the back. The only other person they could book in this role at this point would be Hulk Hogan, and that's not going to happen.
Following this, however, the next time Sting should wrestle should be Bound For Glory. I didn't like the "taking my ball and going home" angle with AJ or Storm, but it could be very apropos here. Sting convinces Hogan to lift his suspension, supports him in naming Ray #1 Contender, then loses to him trying to right the wrong. Make Sting look as huge a threat as possible, vowing revenge....only to lose clean as a whistle.
This is an incredibly important title defense for Ray. Other then his TLC/FMM match against Jeff Hardy, this is Ray's first straight up title defense. I don't know the shelf life for Aces and Eights, but if there's any plans on keeping them 'strong', Ray needs a clean win here. No disqualification, no run-ins, just a straight up victory against Sting. Ratings are down with Ray as champion, which worries me that they're going to accelerate the end of Aces and Eights sooner then necessary.
Ray has been, for me, the most interesting champion since AJ Styles. While I don't think Ray or this angle are built for a long title reign such as Roode or Styles in recent years, he needs the belt until Bound For Glory for this to come off successful. Bound For Glory marks a year since the bikers were official TNA members, and it should, as TNA's biggest PPV of the year, mark the date of their demise as well.
Slammiversary is just a stop along the way, and Sting a stop-gap challenger. I'd go with AJ Styles myself-TNA is the "House That AJ built", isn't it?- but that's thoughts for another time. Ray needs this.