Do note the only character I mentioned as being shoehorned was Catwoman. I didn't say Bane and Talia were unnecessary since the whole premise of TDKR did deal with the return of the League of Shadows, or a version of it... which I was fine with on a narrative level, albeit it being, as I said, tiresome because it was uninspiring, or repetitive, or whatever issues were raised when the film came out. Take your pick.
Catwoman, on the other hand, as was discussed to death then, was indeed an uninspiring and unnecessary choice as Batman's forced love interest/quasi-foil/whatever. Just because it was the filmmakers' idea to have Selena Kyle in the film didn't mean they did a good job with her, and it showed.
My point is that they had a wealth of characters to choose from for the final outing. I'm sure the Huntress must've crossed their mind but they saw fit to go with what was in the final product instead, which I thought was a pity.
That's not to say Bane was a poor choice by Nolan, but Helena would've been better IMO. Her circumstances and morals (or the lack thereof) are more relatable to Bruce Wayne/Batman when it comes to the meaning and value of his existence, as opposed to Bane who's just someone for Batman to overcome, be it on a personal level or for the good of the many... which was a good premise, but that, as I said, had been done in Begins and TDK already.