You could do this, except it's the hard way to do the fight, and almost everyone does Runemaster first. If you keep him up your tank healing requirements go through the roof, and it's much more difficult to run 5 healers. This alone removes any benefit you would have received from having a rune.
Additionally, you have immense requirements on positioning, since you want 90% of the raid to be in melee range of Steelbreaker to reduce the raid damage to manageable levels.
ssongraistln, I can see from the logs that you are killing Molgeim first. If you kill Brundir first and wait for Molgeim to summon a fresh rune of power before finishing him off, you should see much higher DPS if the rune is utilized properly, as using the rune along with your speed/wild magic potion in conjunction with a bloodlust should increase your DPS dramatically.