Except that the T'Ong had a crew of Klingons who were in stasis and the ship was running on its own, whereas Voyager faced off against the Klingon D-7 cruiser whose crew were very much awake and travelling for 4 generations... encountered new races, learning, and probably upgraded their weapons in the process.
The Klingons do seem to be leaning a bit more towards weapons, so its not exactly strange they would be focusing on those - while other systems probably weren't much of a priority for them (even the cloak they used - while primitive - was still just enough to fool Voyager's primary sensors - until the crew used a metaphasic sensor sweep because the Klingons probably modified the tech somewhat but didn't change the underlying technology or its weaknesses).