This trophy was one of the more annoying ones. Being tossed around everywhere by force users is never fun. However, with this game type I will say that the kill/assist mechanic is odd. As long as you don't die and hit the enemy a few times you will get credit for a kill as opposed to assist, even if you didn't get the final hit. (thus making Phasma's turrets all the better)
Personally, when playing on the villains side, I played as Captain Phasma. Assuming you're just starting her out, just make sure you keep "The More The Better" boost card upgraded as much as you can. When you lay her turret, do your best to keep in mind that it doesn't shoot at angles. So don't place it at a high point unless your choke point is level to the turret. With this in mind, stay with your group as best you can (just stay back so you don't deal with being force push/pulled everywhere) and try to pressure the enemy ranged. When you walk up to the turret, you can hold square to pick it up without destroying it and putting it on cooldown. Also, try to stay in range of your turret. It has a stun if the enemy jedi come sprinting in after you. If you're more of the video type, here is a neat video that will help explain how to play the Captain:
When on the alli side, I generally played as either Han Solo or Leia. Honestly, I don't have many tips for either of these two. Just attempt to keep your shots well placed. As Leia, use your L1+R1 rifle as often as you can. (It does a lot of damage) Here is a video for Leia to help you learn her if needed:
However, if you're bent on playing one of the force users, I would advise to look up a tips video as there are quite a few mechanics (looking at you parry) that will help you win more often. Here is one of the videos I found neat:
If you'd like to keep track, make note of the amount you currently have from Career -> Multiplayer -> Annihilation (symbol looks looks like crosshairs) and just keep adding to that per game.