The first thing you'd need to do to fight an organized ganktroop like that one is getting a troop of your own. Unless you take command of your random group, I seriously doubt you will have much of a success with a PUG.
I supposed the term "premade group" is well known nowadays. You're trying to take on a group that likely has ingame/outgame communication (like TS3/Mumble) and of course some fotm **** fitting.
One thing you're going to need is CC abilities. Stuff like Photonic Shockwave. Tractor repulsors to push the zerg away and try to single out one of them.
There are ways to tank massive damage.
Hoowever, STO PvP is at a state where there is a L O T of fotm toys and IWINs that makes the game more of a WoW than Star Trek.
To be honest, I hope you are using escorts because it is usually on top of the foodchain if you can't bring CC/organized teamplay.