My main is a Powertech, and I've found that this character is nearly always at the top of the warzone leader boards. After thinking about it for a while, it seems that a tank/protection build will nearly always have the advantage over healing and dps in warzones.
Note: this discussion is based only on warzones in a PvE server. Open world PvP is not my thing.
For starters, there are 4 medals available for protection. Two tiers each for total protection and streak protection (i.e. protection without dying). I've been told by a few team members that my Bolstered hp are pretty beefy for my mid-level (as of this writing, level 26, with about 12,500hp in warzone matches) toon, but otherwise my character is fairly average. These medals have been really easy for me to get in most matches. Every now and again I'll end up in a match where I have a target on my forehead and I don't get both streak medals, but otherwise I have 3-4 medals that I can count on with minimal effort.
Here's the thing. Using the Guard ability doesn't hamper my other activities in the slightest. Outside of needing either to move it around to protect a high priority target once in a while or shutting it off if I'm about to die, it requires next to no attention and time to get 3-4 protection medals each match. And the medals for 10 and 25 kills are easy to get since Guarding doesn't slow my offense much at all. Same goes for 75k damage. So, if I'm awake during the whole match, I get 6 medals almost always. A killing blow is pretty easy and happens most matches. Solo kills seem to be about 50-50 for me. Add all this up, and anything less than 7 medals is a mediocre performance for my Powertech.
Now my other toon I play often is a Commando. Try as I may, I'm lucky if I get a single healing medal per match. It may be my low level (15), but healing requires so much time and attention that I have to partition my time between healing and fighting. So, it's uncommon for my Commando to get more than 3 medals.
I don't think it's just me, since bounty hunters seem regularly near the top of the leader board, both on their teams and overall. It could be that I need to level my Commando up before making a fair comparison. It could also be that the Armstech crew skill doesn't provide as much of a gear bonus as my Powertech gets from Armormech. Or it might simply be that I need to practice healing in Warzones.
For anyone who skipped to the end, the short version is that protection medals seem easier to get along with offense medals since protection doesn't require much attention. Healing requires both time and attention from the healer, which seems to take away from medals for kills and damage.
I would love to hear the community's thoughts on this subject.