I would advise a carnage specc in the line of this :
http://joharaoc.eu/feat?link=v16_116...c8000c7380ccb0
I use that kind of specc for time trials when i have to tank stuff and still stance dance and pull good dps. Brute is just way too much of a turtle specc and ovekill for that kind of situation.
And yes, rally will give you better result when it comes to just take aggro and hold it for like 10-15 seconds. That being said, i for one would still use BFC, just because of the overall dps increase.