I am a 97 paladin and will sometimes have agro problems from 100+ BLM. Thats normally right at the very end of the mass pull though. The best you can do is flash on your way through, get to kill location, fight or flight -> Flash until OOM and then riot blade combo and flash some more. If you are really having problems with threat you could buy some HQ mana potions for that additional flash. For the most part you should never be halone comboing anything until the last 2-3 mobs, thats when my threat starts to go down hill on everything else.

Best of luck to you.