Yes, anyone could kill a Horcruxless Voldemort.
Dumbledore goes to great pains to explain to Harry that the prophecy does not have inherent validity. The validity of the prophecy is that Voldemort accepted it. As such Voldemort would not rest until he killed Harry, which meant that practically one of them would (probably) end up killing the other. The following two excerpts are from Chapter Twenty-Three of Half-Blood Prince. You may want to read the whole conversation there for the full context but what follows are, I think, the most important paragraphs:
"But," sputtered Harry, "but you said the prophecy means —"
"If Voldemort had never heard the prophecy, would it have been fulfilled? Would it have meant anything? Of course not! Do you think every prophecy in the Hall of Prophecy has been fulfilled?
"Of course you would!" cried Dumbledore. "You see, the prophecy does not mean you have to do anything! But the prophecy caused Lord Voldemort to mark you as his equal.... In other words, you are free to choose your way, quite free to turn your back on the prophecy! But Voldemort continues to set store by the prophecy. He will continue to hunt you... which makes it certain, really, that —"
"That one of us is going to end up killing the other," said Harry. "Yes."
Compounding the situation is the fact that a piece of Voldemort's soul is lodged inside of Harry. In order for Voldemort to be killed, Harry has to be killed first. Since Harry had to die regardless, Dumbledore decided to have Harry be the one to do everything in the fight against Voldemort so that no one else would have to die needlessly. Harry realizes this at the end of Deathly Hallows after seeing Snape's memories:
Dumbledore’s betrayal was almost nothing. Of course there had been a bigger plan; Harry had simply been too foolish to see it, he realized that now. He had never questioned his own assumption that Dumbledore wanted him alive. Now he saw that his life span had always been determined by how long it took to eliminate all the Horcruxes. Dumbledore had passed the job of destroying them to him, and obediently he had continued to chip away at the bonds tying not only Voldemort, but himself, to life! How neat, how elegant, not to waste any more lives, but to give the dangerous task to the boy who had already been marked for slaughter, and whose death would not be a calamity, but another blow against Voldemort.
So again, Harry being the one to kill Voldemort was not a technicality, but a practicality. If, for whatever reason, Harry would be unsuccessful at killing Voldemort, someone else would have to do it. Harry himself acknowledges this:
But Dumbledore had overestimated him. He had failed: The snake survived. One Horcrux remained to bind Voldemort to the earth, even after Harry had been killed. True, that would mean an easier job for somebody. He wondered who would do it... Ron and Hermione would know what needed to be done, of course... That would have been why Dumbledore wanted him to confide in two others... so that if he fulfilled his true destiny a little early, they could carry on...