I'm having a lot of fun doing a cabal/pirate king playthrough, where I kick out of every system I can everyone except for pirates, LP & I install a cabal submarket somehwere in the system so my systems are crawling with underworld raiders. To keep up with the theme my fleet is all cabal or otherwise elite or phase ships then my faction is only allowed to use low tech or pirate/LP variants of midline so that my fleet is always technologically superior. If I get a blueprint for high tech stuff I sell it instead of consuming it so my faction can't have them. I sold a paragon blueprint lol
In fact, once I got stuck defending one of my systems from back to back to back to back to back invasions (everybody hates me) I just accepted that I was gonna have to do all the defense manually & set my fleet doctrine to only prioritize A-Kites & hammer torps then deleted all kite variants except for one with expanded missile racks, then set fleet size to max, ship size to minimum, all warships, aggressive/reckless. So my defense fleets that would try to help were restricted to just torpedo kites to make kill-shots against ships that my fleet had disabled/opened up to a hammer torpedo up the tailpipe. It was actually quite fun.
And for the record, this playthru is extremely hard.