I've seen this opinion voiced before, but really, I just don't see how it could have worked. Even taking into account TOS Klingons weren't noted for honor the way TNG onwards Klingons are, Kor and Kang were still honorable individuals who I can't see filling Chang's role in TUC. Kor in particular, laments when he's announcing his intent to execute Kirk how unfortunate it is he has to kill an actual soldier while the "sheep" he was trying to defend get to continue living. With that in mind, I don't see him framing Kirk for assassinating the chancellor and arranging an "accidental" death for him at prison. Likewise Kang seems the more direct sort, if he wanted Gorkon dead, he'd kill him and take credit for it, if he wanted to sabotage the peace treaty between the Federation and the Klingons, he'd launch an attack on the Federation. I don't see him engaging in an elaborate ruse of framing Starfleet officers to assassinate the chancellor and conspiring further to assassinate the Federation President.