If you have a reference, even a non cannon reference ...
Why would I use something that's non-canon as a reference?
Voyager is closer to the camera than the cube.
No it not, and here's my proof of that.
The battle between the baby "tactical" cube and Voyager begins at about the two minute mark.
Voyager fires two torpedoes on it's approach. The cube fires three times, first as Voyager approaches, second while it is along side, and third after it passes. The image that you
provided a link for is inbetween the second and third firings.
The second firing is from the upper edge and is down onto Voyagers shields. Voyager is along side the cube at this point.
The third firing is as Voyager recedes, striking Voyager's shields from behind. Given Voyagers position inbetween firings two and three is about even with the far face of the cube, the cube isn't even 700 metres square, it's smaller.
It definitely isn't over 3,000 metres.
Other wise, I am going to assume that I am correct
And now you know you're not.
something other than your own personal opinion
Not my opinion, just the facts from the episode, and measurements based on Voyagers width (132 metres).
In that video, at 2:11 is where I took the snap shot. Voyager is parallel with the cube, not in front of it, my bad. But it certainly is not behind the cube.
As for having a non-canon reference, sure, I'd like to see it.
Thus far, you're the only person claiming the class 4 tactical cube is under powered compared to a regular cube.