Pvp rating makes no sense

There's a lot of missing information. What's your team? What was their team?

Focusing on healers could potentially be a very bad strategy depending on the teams.

Also the power of teams is not a 100% accurate representation of how strong a team actually is.

Speee is the most important part of arena. Look at that also.

The composition of the team matters infinitely more than its power to determine your chances of success.
If you have chewie (clone wars), Plo Koon, Ugnaught (lead), jawa and the gamorrean guard, even with 20,000 power more than your opponent, there's 99% chance you'll get crushed into tiny bits before you have time to say "buttstuff".

The biggest question is what were the squads. If you have a hodgepodge of toons and the other person has a squad that has synergy, you are probably not going to do well.

It seems like you're a relatively new player, but you've already caught on to the fact that team ratings don't mean jack sith. Good observation ;)

As the others said, who to target first is dependant upon the composition of both teams.

That being said, as a rule of thumb, you should easily apply more damage than healers can replenish, especially at your level. So, in general, I would target the heavy damage dealers first, then the healers, then the tanks.

One good exception to this rule is if you don't have any debuffers and the other team has a Royal Guard. Take out the RG first, else he will taunt half way through your targets health, forcing you to kill him anyway. By the time you get back to your original target, he probably be back at full health due to the healers. So save time and take him out first.

I've only been playing 3 months, so I am not facing CLS or others the veterans are. My priority is DN, Fett, Biggs, Vader. If any of them are on the other team, I target and focus in that order.

Basically, you need to know the abilities of your toons, the abilities of toons you will be faced against, and how things change when certian toons are on the same team. With a little time and practice, you'll know which teams to fight and which to avoid.

As far as power, it is dependant on your teams synergy. If you dont have it and they do, your gonna want 15% to 20% higher power. In reverse, you can easily defeat those with more power if your synergy is great and theirs is poor.

I suggest you start farming Phoenix if you haven't already. At low to mid levels the are decent in GW and arena, must have to get thrawn, and could be used to get Vader.

But regardless, work on a synergy team for arena.