You can find similar disparities with the Scimitar and other dreadnoughts. Fact of the matter is, all of Star Trek (be it movies and series) are made for TV entertainment and don't necessarily always follow the same rules of ship mechanics, physics, etc. because super attention to detail won't always captivate your audience.
Remember in various episodes of Voyager, borg encounters ended quickly (i.e. Drone, Q2, etc.) while others lasted longer (i.e. Unimatrix Zero). Why you ask? Because it's entertaining that way and suited the plot of the episode.
It's more or less the same in terms of the game. Keep in mind that its purpose is to offer a wide range of MMO game-entertainment while adhearing as close as possible to all aspects of the ST universe. Emphasis on "as close as possible" which means if you have read both star trek encyclopedias from cover to cover, you're bound to find at least a few details they missed.
The latest patch did release borg content for higher levels which probably means you'll see battles alot more similar to that of First Contact and some episodes of Voyager.