I hear that presently the Defensor is considered really strong, mostly because Point Defense against corvettes was apparently nerfed a bit. 

I am not an expert by any means but the Dunov ability Magnetic Singularity which slows enemy movement makes them easier to track for a little bit but I can’t speak to its effectiveness in practice. 

The Shrike corvette will serve you better than the Cobalt or the Kralev because of their slow turning and tracking and the Sova Carrier’s fighters and extreme number of PD auto cannons and ability to make Shrikes on command is a good place to start.