There seems to be a miscommunication here. I don't consider Dosis to be "filler". Well, if you're saying that the primary single target damage button for each healer is functionally the same across classes, then yes, they are indeed quite similar. Though I do have to say that I find the "Eukrasion" gimmick to be neat. Yes, in practice, all it really changes is the amount of space needed on my hotbar for GCD skills. But I still think it's neat, nonetheless. Regardless, that's not the point I was making. The point is that if you ignore differences, you will only see similarities.

I've already discussed several differences between SGE and SCH. I've also already discussed some barriers for further differentiation between healer classes.

If you only want to see the similarities, then I can't stop you. No matter what you choose, I will continue enjoying the game.