The quest says, "do 4 attempts", there is no mention on having to do damage, winning or anything like that.
The next time the raid is done manually, post a short message that you need the raid to run for at least 2-3 min without people fighting (probably not 100% needed, but just in case). Send in your weakest toon by itself, let it die and that is an attempt right there. Wash, rinse, repeat. Within 1 min, you can do your 3 needed attempts.
Now, if you think simming the Rancor raid and doing this quest is an issue, imagine what will happen IF/WHEN the Tank raid is simmed.
There are three separate quests that require a player to get a rank nine times. Do you want to be the player that has to ask management to run the Tank raid 9 times manually just for you? Please CG, don't do this! (An even longer version of the tank sim issue post is attached as a text file, if anybody cares to read it)