My thoughts are simple. Sorry. The actual developers of this game left SS alone for years, not because they didn't get around to "fixing" but because they knew that the set was fun the way it was and a lot of players enjoyed it. "Balance" does not always trump fun or playability or other, immutable values that can't be punched into a spreadsheet and argued about in forum math pvp.
Furthermore, changing sets that are considered "too strong" (I'm avoiding the term nerf here because the rage thing is being considered a bug fix) will only result in that set being abandoned by players who will all flock to the next best farmer. Evidence, go to AE in Atlas Park and tell me how many Spines/Fire Brutes you see.
IMO you put SS back to the way it was and leave it at that. This is a completely unnecessary change. You don't need to rebalance the whole powerset. Just undo the rage change and that's it.
Some changes this team has been working on are positive changes to sets that long needed the update (devices) but this is definitely not one of them.
I wanted to add here that although my memory is fuzzy at this point, I do not remember that the devs actively balanced/nerfed/buffed the game around the behavior of the the 1% farmers except in extreme circumstances or exploits (herding whole maps pre-aggro cap) and even if they had to, they never just fucked over the playability of the whole powerset, nor flat nerfed somemthing without bringing it up somewhere else. They never touched Fire/Kin controllers, SS/Fire Brutes, etc... Because they knew that was only a small subset of the player base and it wouldn't be fair to other players to have their sets nerfed because they were good farmers.
This is one of the reasons why this change to Rage feels so arbitrary and overdone.