Hit xandas and terrans with a proportionally big Co fleet. Zikonian Co is absolutely a cnut to kill.
If you were willing to sacrifice some cutlasses to hit Xandathrii, then I`d hit the typical Vsh+Lancer xanda with cutters+cutlasses+privateers. For terrans, dragons aren`t at all effective against ziko co, so you can easily flak through them once again with cutters+privateers(and thieves heh.)
The Cruiser roiding fleet option is quite limited apart from other zik or caths. If you want to hit terran or xandas, you must rely on them having small numbers of bombers or pulsars and drakes. As you can send a clipper+cr fleet against xand to subvert his bombers but obviously, if he has a big amount of pulsars, your clippers will get raped and the roids will most likely be too expensive
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As aforementioned, Zik CO is the way to go(i can`t believe i just made it rhyme there :/)