At 16-17, the fights with gorge hounds were more predictable because I could tell which ones were higher, but now at 18 they're all dark blue. I've been putting my DS on pet so usually it comes out ahead and I can all but guarantee a one-nuke kill to the target and not worry about my pet dying if it's lower hp and the target resists root. I guess if I DS a higher level mob it has a big advantage.

I would probably get rid of the DS on pet then and simply put a DoT on the mob your pet is fighting if you see the ties against your pet. You will have more control on the fight this way.

Anyway - you will find this becomes much easier at higuer levels when root is more reliable.

Good levelling !!