I could imagine to beat the boss as dps with the alysrazor buff, but sadly if you're dmg specced, you get shards and while the dmg of them itself is already considerable, the debuff gets you killed instantly on the next shard/blades.
Dunno if the alysrazor buff could have enough impact for a class to push that guy to zero witihin 30-40 seconds, might even be wort a try as high end unholy, but very highely unlikely.(garg does around 5 million for me normally, with 100% crit, BL drums, 200% more multiplicative haste it could reach like 30-40 million, army output similar, but i doubt that the dk itself + timmy is capable of taking the other 80 million away in the given timeframe)
I didn't do Baleroc in a while, but i remember killing him normal with 530ish gear with like 150k dps, well that was pre vengeance nerf but with like 40 ilvls more doing like 170k to beat that hc enrage seems easily doable. (no drums and stuff, just 500 all stats flask and cheap str food)
How far are you from the kill? and majordomo hc?
Logs would be nice to have a look at your situation.
I did a BoT 10man heroic run as unholy yesterday and it was kinda funny, didn't manage to get Cho'Gall down (best try around 7%/3million hp) p2 is incredibly stressful as you are dead if the adds get a cast on you, the boss can literally two shot you, also you have to get him down to 25% quite fast to avoid getting too many stacks, resulting in being unable to outheal his attacks.
Getting 25 corruption pre p2 is also a wipe and to avoid getting more than 3 stacks you need to burn that boss even if a second add spawns, resulting in very high spiky dmg. Also if he gets a fire ele directly from the transition you're also pretty dead.
I know its easier as blood, but also kinda boring, like the challenge of doing stuff as dps, preferably unholy.
Did Sinestra with a second one, but seems doable solo as unholy, if you don't get that ticking debuff though, need to have another look at that.
Halfus, V&T and Ascendant Council were doable somewhat well. Dmg income on V&T is kinda high and i took in LB to save myself in the transition, as soon as you get engulf magic, if the boss isn't dead then he should die by then.
Council and Halfus were kinda trivial, burst dragons on halfus, beat the crap out of him (took 3 dragons, nether, stone, bronze) and after they were dead the fight was pretty much over,
council -> nuke -> council dead
Shows normal, is heroic, you can see it by dmg amounts.
Gonna go for BWD hc next time.