A user and the pet have separate hate. Carby does have some some enmity increasing skills so enmity is never a good indicator of damage.
Dots are good and bad. Dots do not over write thus you can have bio bio bio bio2 etc etc, from many casters, but at the same time enemies will resist more and more the longer the fight, as well as the fact those dots aren't exactly strong.

All classes have dots, most of them just suck. it is fairly easy to calculate how much damage a dot does and rarely do they exceed the damage of a straight up attack.

Finally Buffs and crits obviously do not favor dots so dots loose out simply because they are not good at ability stacking.