I am a healer and I don't really think they should add more medal for it.
Why? Simply because they would have to add more dps medals for the same values and then your back to where you started.
If we look at the diffrence between a dps and a healer.
The healer got 2,5k, 5k, 75k and 300k healing medals.
The dps gets 2,5k, 5k, 75k, 300k, 10 kills, 25 kills, killing blow and solo kill.
A healer can usually get a killing blow without problems, (and 25 kills if you ain't stupid and want medals), but I would say that they should give kills to the healers assisting those who kill the other players.
Then the only diffrence would be killing blow and solo kill and in a typical wz the killing blow is easy tog et for most people while the solo kill can be a *****.