Yes...Totally different...As were the Earth Navy capitals from Colony Wars: Vengence

Yet the Navy capitals would not look out of place in the B5 universe...I suspect that they may have had the same designers or the designers were b5 fans.
Also many of the terran capitals from FS1/2 look like theyd fit into the b5 universe quite well.
The Karuna looks like a next-generation vessel from the Post-Drakh invasion...I suspect Steve-O is a B5 fan because the Karuna clearly is heavily inspired by the omega destroyer and the Oracle or Sagittarius cruiser
(These last 2 are canon ships that never appeared in the series. They were part of the ships designed for the cancelled B5Wars game and was later inculded in the B5 RPG. According to what ive heard, the ships that were designed for B5Wars
ARE Canon)

lets take a closer look at that \/

Sagitarius cruiser Oracle Cruiser
See the similarity between the Karuna and both ships. All that left to do is add the Omega's Antenae complex to the front and the the Rotating section between the oracle/sagittarius bridge section (The part with the raised area near the back) and the engines and you are essentially left with the Karuna