That's really bad, actually.
It's really bad because it means that, from Tuvok's perspective, the ship would have been lost if they hadn't gotten lucky. It would be one thing if he'd predicted that Ensign Laurence could hold off 6 Kazon by himself and assigned him accordingly, but instead what happened is that almost the entire security team was needed to prevent the bridge from falling. They had a numerical advantage, but not much of one, and his men were ill suited to melee combat. So he'd played to his outs and assumed Engineering would be left alone.
"Commendable."