And what? Have you noticed a fat guy who shoots missiles with ***king big damage and can heal itself?
Only in such stupid game like SWTOR can do damage and heal simultaneously.
In normal games - or damage, or heal.
The only heal a merc/commando will ever be able to use is when he not targeted or he has to blow 2-4 (pretty much all he has) cooldowns to get one off, plus a 2 min cd HoT that barely registers. Your post indicates that mercs are OP...wich reflects kinda bad on your own knowledge about the game im afraid...