Not one, they landed a few Photons on their shields first. Still, you have a bit of a point... except for that that was an alternate timeline. In THIS timeline, two K'Vorts can smack down a Vor'Cha until they drop their shields.
Yeah, the usual problem in Trek: we get to see a proper 1 on 1 battle in far too few cases so we can hardly gauge what power they can actually bring to the table.
I'd imagine the K'vorts we see in "Redemption" would not be an advanced model we'll (hopefully) get in this game but some kind of "missing link" (technologically speaking) between the good'ol K't'inga and the then-state-of-the-art Vor'cha.
So they could probably roughly be translated as either T3 or 3.5 while a T5 would have all the same upgrades the Vor'cha received when it was retrofitted to the high-tech battlecruiser have have in this game.