Honestly we're lucky to even be in the position where that's a possibility. Maybe we win Game 7 because Giannis is Giannis but Boston is so much better and deeper than we are. Khris would certainly help but they're still much deeper.
Horst is an incredibly overrated GM, he was gifted Giannis and Middleton and he's never been able to do much to build around them. Bledsoe was a flop, Nikolai Mirotic gave us nothing. He's surrounded our core with aging vets on their last legs, Ibaka could not have been more worthless of an acquisition and guys like Hill, Matthews, and Allen offer next to nothing. Even Lopez looks cooked.