The PF is a nimble giant with a glass jaw. A good phaser strike from a CL and up will usually make them go pop. So the key is to seperate them from their tender and blow em up one by one. Usualy (As most fighter toting ships) once the PFs are gone, the tender is not as hevaly armed as its non carrier counterparts. Also, when facing a plasma race, keep your speed up and draw out their plasma, i.e get them to shoot while you are headed away.